Knowing when the jig is up and actually doing something about it can’t be an easy choice.

Football is a tough, demanding sport that requires as much athleticism as it does the cerebral capacity to know when the body can’t cash the cheques that the mind wants it to.

Wes Welker was one of those guys. A great receiver in the NFL, despite never being drafted, Welker was a four-time All-Pro and NFL receptions leader three times for the New England Patriots.

But, later in his career concussions took their toll and his play started to decline because of it. After eight fairly uninspired games with the Rams in 2015, Welker’s career was effectively over.

He is now an assistant coach with the Houston Texans.

Welker is an exception, unfortunately, as there are several aging NFLers who may be in denial about their own declining play and prospects.

Here are 15 who should take a long, hard look at their career and maybe call it quits, sooner than later.

15. WR Victor Cruz – Free Agent

As far as lengthy careers go, Cruz really hasn’t spent that much time in the NFL, appearing in 70 games (53 starts) since 2010. Undrafted out of the University of Massachusetts, Cruz had his first experience with the Giants in 2010, playing in three games. But, a harbinger of things to come, a hamstring injury forced him off the depth chart. In 2011, though, he broke through in a big way after initially being a fourth-string receiver. He would go on to catch 82 passes for 1,536 yards and nine TDs. That post-season, he snared another 21 passes from Eli Manning, including a touchdown as the Giants went on to win Super Bowl XLVI. His 2012 season was nearly as prolific, with 1,092 receiving yards and 10 touchdowns, but after that injuries would derail his career. A torn patellar tendon in 2014 pretty much spelled it out and he missed all but six games. He signed a one-year deal earlier this season with the Chicago Bears, but was released on Sept. 2.

(AP Photo/Nam Y. Huh)

14. RB Chris Johnson – Free Agent

Only seven running backs in the history of the NFL have broken the 2,000 yard barrier. Chris Johnson, currently a free agent, was one of those chosen few. After being a late first round pick of the Tennessee Titans in 2008, he had an eye-opening season for the team in 2009, rushing for 2,006 yards and 14 TDs. Johnson also caught 50 passes for another 503 yards and another two scores. His 2,509 combined yards that year are seventh most, all-time. Johnson would have six standout years for the Titans, russing for 7,965 of his career 9,537 yards and 50 of his 55 touchdowns. A move to the New York Jets in 2014 saw his stats decling to just 663 yards (first year under 1,000) and just one TD in 16 games. He had signed a three-year free agent contract, but the Jets declined the last two after that campaign. He rebounded somewhat with Arizona in 2015 with 814 yards rushing in 11 games but broke his leg and missed that last quarter of the season. In 2016, he was replaced by David Johnson and suffered a groin injury. He was waived on Sept. 1 this year.

(AP Photo/Rick Scuteri)

13. QB Ryan Fitzpatrick – Tampa Bay Buccaneers

If it weren’t for the dearth of decent back-up quarterbacks in the NFL, the Amish Rifle might be out of a job. In fact, several NFL players have taken aim at his degraded skills, especially since Colin Kaepernick is out of work, still. The proof that the current Bucs back-up should retire was in his cruddy 2016 season with the Jets. He threw for 2,710 yards in 14 games, along with 12 TDs and 17 interceptions. This was a far cry from his 2015 year in the Big Apple, when he compiled 3,905 yards passing, 31 touchdowns and 15 interceptions. That 2016 campaign had such an odor to it that the lousy Jets voided his deal and he became a free agent. He wasn’t great in the pre-season for Tampa, either, completing 21 of 40 passes for 153 yards and two interceptions. If he doesn’t retire after carrying the clipboard this season, he’ll likely be unemployed by the 2018 season.

(AP Photo/Gary Landers)

12. CB Darrelle Revis – Free Agent

If his fairly illustrious career as one of the best shutdown corners in the NFL in the last 10 years isn’t already over, no one is telling Darrelle Revis. Released at the start of free agency earlier this year, the seven-time Pro Bowler and four-time First Team All-Pro is still without a NFL job. The writing was on the wall for the handsomely paid Revis (he signed a five-year, $70 million contract in 2015) after a mediocre 2016 campaign with the Jets. He had 53 tackles and his lowest number of passes defended in a near full season (15 games) with just five. In fact, opposing quarterback ratings were recorded at 91.7 compared to 59.3 his previous nine years. Revis won a title with New England in 2014, allowing just one pass completion on balls thrown his way in the post-season. The return to the Jets on the big money contract obviously hasn’t worked out.

(AP Photo/Bill Kostroun, File)

11. RB Reggie Bush – Free Agent

Until we found his name on a free agent list, we barely new that former Heisman Trophy winner and Super Bowl champion Reggie Bush was still even considering playing football. His stats with the Buffalo Bills in 2016 bear that out, as he rushed for -3 yards on 12 attempts as a back-up with the moribund franchise. Otherwise, the former dual threat had seven catches for 90 yards in 13 games. These numbers were a far cry from some salad days with Miami in 2011, when he had 1,378 all-purpose yards, or in 2013 with Detroit when he logged a career high 1,512. At one time a celebrated college running back and a savior of the Saints franchise after being selected second overall in 2006 out of USC, Bush became probably more famous for who he once dated (Kim Kardashian) as he was for football. His last 18 games in the NFL, five with San Francisco and 13 with Buffalo, should be enough to convince Bush to retire.

(AP Photo/Mark Tenally)

10. RB Jamaal Charles – Denver Broncos

Most running backs, once they hit 30, are considered “over the hill.” Jamaal Charles, long-time running back with the Chiefs who amassed over 10,000 all-purpose yards in 10 seasons, is one of those geezers. And old running backs almost always run into injury trouble, with Charles being no exception. After playing in 46 games between 2012 and 2014 with Kansas City and over 5,000 all-purpose yards, he tore is ACL in 2015 and was limited to just five games and 541 all-purpose yards. Last year was no better, as he got in just three games and logged 54 total yards. He had to undergo a second knee surgery last year and was released by the Chiefs in February. The four-time Pro Bowler landed with the Broncos on a one-year deal, but you have to think that once Devontae Booker is healthy, he’ll be a third-stringer in the Mile High City.

(AP Photo/David Zalubowski, File)

9. RB C.J. Spiller – Kansas City Chiefs

The writing on the wall couldn’t be any clearer for former Buffalo Bills’ Pro Bowler C.J. Spiller. In the space of six days last week, Spiller was released by the Chiefs (Sept. 2), re-signed (Sept. 3), released again on Sept. 7 and then re-signed on Sept. 8. Pro football, at one time outstanding for Spiller — he had 1,703 all-purpose yards in 2012 with the Bills — has become a relentless slog of team-switching for Spiller in the last two years. He spent 2015 with the New Orleans Saints after five seasons in Buffalo, running for 112 yards and catching 34 passes for 239 yards and two TDs. He was released early last year by the Saints, then spent two games with Seattle before being released and then another four with the New York Jets before getting cut. Right now, he is third on the depth chart behind Kareem Hunt and Charcandrick West.

(Winslow Townson/AP Images for Panini, File)

8. SS Donte Whitner – Free Agent

In his 11-year career, Donte Whitner was a reliable safety who didn’t miss a whole lot of games and put in yeoman’s work in four different defensive backfields. He was drafted eighth overall by Buffalo in 2006 out of Ohio State and became one of their better defenders for five seasons. A move to San Francisco in 2012 proved fortuitous, as he went on to appear in the first of his three straight Pro Bowls (twice with San Fran once with Cleveland). A feared hitter, Whitner signed with the Browns in 2014 for four years and $28 million. However, even a bungling Browns franchise could realize when a player is on the downslope, releasing him in early 2016 and saving nearly $4 million in cap space. Whitner appeared in 11 games (nine starts) with Washington, where he registered 66 tackles, but zero passes defended for the first time in his career.

(AP Photo/Ron Jenkins, File)

7. DE Julius Peppers – Carolina Panthers

At this stage of the game, suffice to say that Julius Peppers is playing out the string with the team that originally drafted the North Carolina native. Now, Peppers, 37, doesn’t necessarily hurt the Panthers on the depth chart, but the durable defender’s best days are clearly behind him. He is second on the depth chart to LDE Charles Johnson and registered a tackle and a half sack in his first game back with the Panthers on Sunday. A nine-time Pro Bowler and six-time All-Pro, Peppers played his best football with the Panthers early in his career, logging 308 of his career 521 tackles (to that point) and 81 of his career 135.5 sacks. Last year, with Green Bay, Peppers played in all 16 games, but had just 23 tackles and 7.5 sacks. This is probably his NFL swan song with Carolina.

(AP Photo/Bob Leverone, File)

6. LB Tamba Hali – Kansas City Chiefs

Perhaps it’s telling that when looking at the Kansas City Chiefs depth chart, on their very own website, that of 10 linebackers in the Chiefs’ 3-4 scheme, Tamba Hali’s name doesn’t even appear. The 12th-year pro didn’t appear in Kansas City’s electric come-from-behind 42-27 victory over New England last Thursday and not long ago had voiced his frustration, via Twitter, on his lack of playing time in 2016. Hali openly opined whether he was needed anymore in K.C., considering he started just twice in 16 games during the 2016 campaign and recorded a career low 3.5 sacks. A five-time Pro Bowler and two-time Second Team All-Pro, Hali had three seasons of double-digit sacks not that long ago. With all those linebackers on the Chiefs roster, one has to wonder if Hali does fit in at all, considering Twitter rant.

(AP Photo/Don Wright)

5. DE Dwight Freeney – Free Agent

A Super Bowl champion, seven-time Pro Bowler, four-time All-Pro and AFC Defensive Player of the Year (2005), Dwight Freeney’s career, sadly, is all but over. Dwight Freeney, who enjoyed his best seasons in Indianapolis, appeared in 15 games for the NFC champion Atlanta Falcons in 2016, recording 10 tackles and three sacks. A first round (12th overall) pick in 2002, Freeney had a career year in 2004, leading the NFL in sacks with 16, one of seven seasons in Indy that he recorded double digits. Over the past four seasons Freeney has bounced around, first with the San Diego (now L.A.) Chargers in 2013-14 and then Arizona (2015) and Atlanta (2016). He is currently ranked 18th all-time on the sack leaders list with 122.5.

(AP Photo/Mark Humphrey)

4. TE Antonio Gates – Los Angeles Chargers

There is a trio of contenders for Antonio Gates throne as the Chargers’ starting tight end. The popular Gates has played every one of his 14 seasons with the Chargers and if he falters in 2017, guys like Hunter Henry, Sean Culkin and Sean McGrath are champing at the bit to replace him. It will be a tough job, considering the 37-year-old eight-time Pro Bowler and five-time All-Pro has been nearly invincible, missing just 20 of 224 games in his long career. However, Gates did have his least productive season since his rookie year, catching 53 passes for 548 yards and seven TDs in 14 games last year. Thus, Father Time is stalking one of Philip Rivers’ favorite targets. It’s only a matter of time before he should hang up the cleats.

(AP Photo/Jae C. Hong)

3. QB Eli Manning – New York Giants

We don’t believe that Eli has the career staying power that his sure-fire Hall of Fame brother Peyton had. And should this season go south after a week 1 thrashing by division foe Dallas (19-3), the calls for Eli to retire might grow. If things weren’t bad enough Sunday, Manning was on the wrong end of a sack while his offensive line was introducing themselves in a televised bit while the game was running in the background. In all, the two-time champion and Super Bowl MVP was sacked three times and finished the game 29-of-38 for 220 yards and an interception. Now in his 14th season with the Giants, Manning saw some regression in 2016, with 4,027 yards passing, 26 TDs and 16 INTs. This followed a pretty good 2015, where threw for 4,432 yards (second most in his career), 35 touchdowns and just 14 interceptions. Time may be catching up with him.

(AP Photo/Michael Ainsworth)

2. TE Marcedes Lewis – Jacksonville Jaguars

It was good news, bad news for the Jacksonville Jaguars in week 1. They got a big win over division rival Houston, 29-7, but in the process lost star wide receiver Allen Robinson for the season after he tore his ACL. One player who may benefit from extra targets is 12th-year tight end Lewis, who had two targets Sunday and failed haul either one of them in. A Pro Bowler in 2010, the career Jaguar has steadily declined since then, to the point he caught just 20 passes in 10 games last season for 169 yards and a lone touchdown. Third stringer James O’Shaughnessy, in his third season as a back-up (first with Jacksonville) was the lone tight end to catch a pass Sunday. On the depth chart, too, is second-year tight end Ben Koyack, who had similar stats to Lewis in 2016 during his rookie season.

(AP Photo/Tim Ireland)

1. QB Carson Palmer – Arizona Cardinals

At 38, the end may be coming nearer for 14-year veteran pivot Palmer. He struggled mightily in Arizona’s 35-23 loss to Detroit on Sunday, completing 27 of 48 passes for 269 yards and a touchdown. But, he was intercepted three times and sacked once. The Cards had actually taken an early 10-0 lead, but Palmer’s second pick of the game set up Detroit’s first touchdown. What is truly troubling is that the aging signal-caller took plenty of time off in the off-season to rest his arm in advance of the season. A three-time Pro Bowl participant and Second Team All-Pro in 2015, Palmer slipped somewhat in 2016 from lofty numbers the previous season (career high 4,671 yards passing, 35 TDs, 11 INTs). The Cards went 6-8-1 and Palmer passed for 4,233 yards, 26 TDs and 14 INTs to drop his passer rating from 104.6 in 2015 to 87.2.

(AP Photo/Duane Burleson)