By all accounts, being a professional athlete is a very rewarding and worthwhile experience. Money, fame, and getting to play a game you love each and every day are just some of the many benefits. However, all good things must come to an end. For professional athletes, that end is usually when they decide to retire.

While most athletes will stick around as they can, both for competitive and financial reasons, others have decided to retire early. Their reasons for early retirement often vary, whether it be burn out, injuries, or something else. But there is no doubting that these 15 players could have still been major contributors to their respective teams, had they not called it quits.

15. Brandon Roy

While he was the starting shooting guard for the Portland Trail Blazers from 2006-2011, Brandon Roy was one of the best players in the entire NBA. After a solid college career, Roy won the 2007 NBA Rookie of the Year and as soon as he entered the league, looked to be one of the best shooters out there. He also made three All-Star games from 2008 to 2010. However, Roy didn’t have the best knees and went through numerous injuries and surgeries, but nothing seemed to help. Roy retired in his prime at the age of 27. Who knows how good he could’ve been if he was able to stay healthy.

(AP Photo/Greg Wahl-Stephens)

14. Bjorn Borg

Bjorn Borg will go down as one of the best tennis players of all time. He rose to fame as a teenager and during the 1970s helped the popularity of tennis skyrocket. He won ATP Player of the Year five straight times and made 16 different Grand Slam finals. He was well on his way to rewriting every record in the books, before he shocked the world and retired in 1983 at the age of 26 after simply burning out from playing so much the previous few years. He made an attempt at a comeback in the 1990s, but he wasn’t able to do much and the game had passed him by.

13. Patrick Willis

Patrick Willis was one of the most underrated and talented linebackers to play in the NFL over the last decade or so. Willis was drafted by the 49ers in 2007 and would go on to make the Pro Bowl in each and every single season of his career, while also being named an All Pro every year but his final. Willis shocked the world after the 2014-15 NFL season when he announced his retirement from football. He was still in his physical prime and not even 30 yet, but foot and toe injuries prevented him from feeling like he could play as well as he should. He only played in six games that final year, contributing to his decision.

(AP Photo/Paul Sakuma)

12. Rocky Marciano

In the argument of “who is the best boxer of all time?” the name Rocky Marciano isn’t thrown around enough. Marciano not only retired the heavyweight champion of the world, but also retired with a 49-0 record, making him the only heavyweight champ to ever retire without losing a single bout. Marciano also had 43 knockouts, which is the highest knockout percentage ever among heavyweight champs. As you could imagine from the unique name, Marciano was the inspiration for the Rocky movies and is a true legend in the sport of boxing. Marciano decided to retire at 32-years-old to spend more quality time with his family. Between that and the brutal amount of punishment the sport dishes out, we can’t blame him for hanging up the gloves for good. However, it’s very possible he could have fought for a few more years — George Foreman reclaimed the heavyweight title at 45, after all!

(AP Photo, File)

11. Mike Bossy

During the early 1980s, the NHL was dominated by the New York Islanders as they won four Stanley Cups (and narrowly missed a fifth) in that period. This amazing success was largely because of their best player Mike Bossy. Bossy was a scoring machine and throughout his entire career averaged a crazy 1.5 points a game. He also scored 50 goals in a season nine straight times, with five of those seasons seeing him put up over 60. Despite the amazing start to his career, his time as an NHL player was cut short due to nagging back issues. He was forced to retire at 30-years-old in 1988. There is a chance that if he stayed healthy and played longer, he could have had the most goals in NHL history. He retired with 573 goals. If he put up another six or seven seasons of around 50 goals, he would have been close to Wayne Gretzky’s all-time record of 894.

(AP Laserphoto)

10. Annika Sorenstam

There have been many outstanding female golfers throughout the years, but arguably none of them have been better than Annika Sorenstam. She has 72 career victories, including 10 majors, and has a whopping eight LPGA Player of the Year awards. With all of these amazing accolades under her belt, it was even more shocking when she decided to retire at the age of 38 in 2008. While 38 might seem old for a pro athlete, it is actually quite young for a pro golfer. Many golfers can still perform well into their 40s and 50s, so Sorenstam definitely could have stuck around for at least a few more seasons. There is no doubt that the Swedish star will go down as one of the best and most influential golfers of all time.

(AP Photo/Stephen J. Carrera)

9. Yao Ming

There have been some hyped NBA prospects throughout the years, but very few have been able to achieve as much hype as Yao Ming did. Yao came into the NBA as the first overall pick in 2002 and he was a rare physical specimen. He was 7’6″, and could run the floor like someone a foot shorter. He put up some truly outstanding numbers early on and was one of the most dominant big men of all-time. Additionally, you could argue he was one of the first international superstars of the game, helping grow basketball globally as he attracted a huge Chinese fanbase. Sadly, he developed major foot injuries a few years into his career and ultimately had to retire at the age of 30. He will go down as not only one of the best centers ever, but one of the most important and popular players in league history as well.

(AP Photo/Darron Cummings)

8. Calvin Johnson

There have been a lot of freak athletes to suit up for an NFL team, but perhaps none as special as Calvin Johnson. Johnson was a rare mix of speed, strength, and size and dominated the NFL as a wide receiver during his career. He made six Pro Bowls and was named an All Pro four different times. He led the league in receiving yards in both 2011 and 2012, and was a nightmare for opposing defenses to cover. However, after nine seasons in the NFL, Calvin Johnson decided to call it a career in early 2016. It was a combination of the Detroit Lions awful teams (where he was often the only bright spot) and the worry about how his body react if he played too long in the unforgiving NFL. There is a good chance he could still be playing today if he wanted to, and would likely still be able to put up 1.000+ yards a season.

(AP Photo/Paul Sancya, File)

7. Ken Dryden

Ken Dryden is one of the single best goaltenders in the history of the NHL, and had he stuck around longer, might have been the consensus best of all-time. Dryden not only won five Stanley Cups in the 1970s with the Montreal Canadiens, but also had outstanding statistics as well. He won nearly twice as many games as he lost and was just incredible for the Habs between the pipes. He probably could have played for another decade (or more), but decided to call it quits after just seven NHL seasons at the young age of 31. Since retiring, Dryden has had a political career, been a hockey commentator, and also became a lawyer. He has been busy!

6. Jim Brown

While he hasn’t played in many decades, Jim Brown is still seen as one of the greatest NFL players to ever put on an NFL uniform. After a successful college career, Brown was drafted by the Cleveland Browns in the first round. He then went on to have one of the most dominant careers of any player in history. He made nine Pro Bowls, was an eight-time first team All Pro, and won three MVP awards. He shattered records during his career and was the leading rusher in the NFL for eight seasons. Brown retired at 30 after only nine years in the NFL and if he would have stuck around, there is a good chance many of his rushing records would still stand today.

(AP Photo)

5. Sandy Koufax

Even though he played during the 1960s, Sandy Koufax is still seen as one of the best MLB pitchers of all-time. His list of accolades and achievements is unmatched at the position and there was no one better in his era. He won four World Series championships, three Cy Young awards, and even an MVP (all with the Dodgers). He also pitched four no-hitters and was one of the first people to ever throw a perfect game. He had nearly twice as many wins as losses and threw well over 2,000 strikeouts in his storied career. Sadly, elbow issues forced Koufax into an early retirement at the age of only 30. He would go on to be inducted into the Hall of Fame at the age of 36, which is the youngest ever.

(AP Photo/Harry Matosian)

4. Bobby Orr

It is likely we will never see another player like Bobby Orr in the NHL. He helped to revolutionize the position of defenceman with speed, scoring, and a great passing ability. He is considered the best defenceman of all time, and some even think he is the best player period. He won two Stanley Cups and his individual award wins are legendary. He won eight straight Norris Trophies, three straight Hart Trophies, and even won a couple of Art Ross trophies, being the only defenceman ever to win the award. He struggled through many injuries (mostly to his knees) before ultimately deciding to retire in 1978 at the age of 30.

3. Bo Jackson

It is hard enough to become a professional athlete in one sport, let alone two. A few people have done it, but none better than Bo Jackson. Jackson not only played in the NFL and the MLB, but he managed to excel at both. In fact, Bo Jackson became the first player to be named an All-Star in the MLB and a Pro Bowler in the NFL. He managed to play in both leagues at the same time (football in the winter, baseball in the summer) and put up great stats in both. However, in 1990, a hip injury would force him to retire from the NFL. He would still play in the less physically demanding MLB for a few more years, but eventually had to give that up too. All in all, it would’ve been great to see Bo play in both leagues for a bit longer had injuries not reared their ugly head.

(AP Photo/Leonard Ignelzi, File)

2. Michael Jordan

While Lebron James is knocking on the door, Michael Jordan is still the greatest basketball player of all-time to most people. During his career, Jordan has done just about everything you could do, from winning multiple championships, many MVPs, a few scoring titles, and traveled to well over a dozen All-Star games. However, many of those accolades would have never stuck if Jordan had stayed retired. Jordan’s first retirement came in 1993 in the wake of his father’s death, where he infamously wanted to try his hand at becoming a professional baseball player. Thankfully, he came back into the league a couple of years later and picked up right where he left off, winning three more championships and cementing his legacy. However, retiring in the prime of your career as one of the best players in the NBA definitely counts as retiring too early — even if he did come back.

(AP Photo/Karl DeBlaker)

1. Barry Sanders

This one likely still irks Detroit Lions fans to this very day. Barry Sanders followed up an amazing collegiate career with a Rookie of the Year victory in his first NFL season. Sanders would go on to not only lead the Lions to the playoffs five times, he would also win an MVP and go to ten straight Pro Bowls. He was one of the most elusive running backs of all-time and was very difficult to tackle. He was one of the best players in the NFL throughout the 1990s and was well on his way to becoming the rushing yards leader in NFL history. However, in 1998, he retired out of nowhere at the age of 31, shocking millions of people. There was no injury to report and he had signed a large six-year contract just two seasons earlier. There is no doubt Sanders could have secured the NFL rushing record had he played in the league longer, as he was only 1,500 yards behind all-time leader Walter Payton when he called it quits. He could put up those numbers in an average season.

(AP Photo/Jeff Kowalsky)