20 famous athletes who retired earlier than expected

Sport: Football

Age retired: 29

Years as a pro: 9

One thing to know: Gronkowski might have gone down as the greatest tight end ever if not for injuries. Gronk dominated every time he was on the field, but various ailments kept him off it, as he only played 15 games or more four times in his career. After rumors of retirement persisted for over a year, Gronkowski followed through in the spring of 2019. However, some think he could still be lured out of retirement.

Sport: Football

Age retired: 30

Years as a pro: 8

One thing to know: Baldwin was Russell Wilson's favorite target for several years, topping 1,000 yards twice, including a 14-touchdown season in 2015. Injuries added up throughout 2018, and despite finishing the year with over 600 yards and 5 touchdowns in 13 games, he called it quits in 2019.

Sport: Basketball

Age retired: 29

Years as a pro: 6

One thing to know: Roy was one of the NBA's best guards and rising young talents when he ran into persistent knee problems. He initially retired in 2011 after just five years with the Portland Trail Blazers but came out of retirement after one year to play for the Minnesota Timberwolves in 2012-13. He played only five games that year before injuring his knee again, and the team waived him at the end of the season. He decided to hang up his jersey for good afterward.

Sport: Baseball

Age retired: 30

Years as a pro: 12

One thing to know: Koufax is widely regarded as one of the best pitchers in MLB history. He was seemingly playing his best ball before he retired, posting a 1.7 ERA with 5 shutouts and winning the Cy Young Award in 1965, his final season. However, chronic pain from injuries forced him to end his playing career in 1966.

Sport: Football

Age retired: 30

Years as a pro: 8

One thing to know: One of the most dominant linebackers in the league, Willis managed just six games in his final season because of injuries. He announced he would retire the next offseason, saying he couldn't get over pain in his feet. He was a five-time All-Pro member.

Sport: Hockey

Age retired: 31

Years as a pro: 12

One thing to know: One of the best defensemen in NHL history, Orr took a beating during his career. After leaving the Bruins, where he built a legendary career, he managed just 26 games in two seasons with the Blackhawks. He retired in 1979.

Sport: Tennis

Age retired: 26

Years as a pro: 12

One thing to know: Borg was described as a rockstar on and off the court for his looks and icy demeanor during his sharp rise through the tennis world. It was a shock, then, in 1984, when Borg decided to retire at just 26, after winning 11 grand slams, citing mental burnout. He did attempt to come back in 1991, but was largely unsuccessful on the court and retired again in 1993.

Sport: Football

Age retired: 30

Years as a pro: 9

One thing to know: "Megatron" was the clear-cut best receiver in the NFL for multiple years and still put up 1,200 yards and 9 touchdowns in 2015, his final season. Johnson later admitted he retired because he didn't feel like the Detroit Lions had a chance to win a Super Bowl and they wouldn't trade him another team. "For the work I was putting in, it wasn't worth my time to keep on beating my head against the wall and not going anywhere," he later said.

Sport: Basketball

Age retired: 30

Years as a pro: 9

One thing to know: Yes, it wasn't final, but Jordan's first retirement was so abrupt that he lands on this list. Jordan was on top of the NBA when he suddenly announced he was retiring to pursue a baseball career, spurring conspiracy theories. Of course, he would return in less than two years, play three more seasons, retire again, come back again as a member of the Wizards for two seasons, before then retiring for good.

Sport: Football

Age retired: 29

Years as a pro: 9

One thing to know: One of the first "shocking" retirements in sports, Brown was an eight-time rushing champion and NFL MVP in 1965, his final season. He decided to go out while on top, though he was also busy filming "The Dirty Dozen" and pursuing other business interests that conflicted with the NFL schedule.

Sport: Football, baseball

Age retired: 28 (football), 31 (baseball)

Years as a pro: 4 (football), 8 (baseball)

One thing to know: Considered one of the best athletes of all-time, Jackson managed to play two sports at once, playing football with the Oakland Raiders when the MLB season ended. Jackson suffered a career-ending hip injury in the 1990 NFL season, then returned to baseball to play two more years, but was not the same player. He retired for good in 1994.

Sport: Basketball

Age retired: 30

Years as a pro: 9

One thing to know: Yao's time in the NBA was relatively short, though it came after a stellar career in China. An instant-celebrity by the time he arrived in the NBA, Yao also excelled on the court, averaging 19 points and 9 rebounds per game in eight full years in the league. Unfortunately, chronic foot injuries ended his career early.

Sport: Hockey

Age retired: 31

Years as a pro: 8

One thing to know: Dryden had a decorated career in just seven seasons as a full-time goalie: a Conn Smythe Trophy winner, five-time Vezina Trophy winner, six-time champion, and three-time leader in save percentage. He ultimately decided to move onto other things and wrote several books, did commentary, and worked as a GM after retiring.

Sport: Football

Age retired: 31

Years as a pro: 10

One thing to know: Sanders was still at the top of his game when he decided to step away from football. He had rushed for over 2,000 yards just two seasons before. But Sanders later said that he had been pondering retirement at the beginning of the 1998 season (his last) and decided to step away from football afterward, despite being just 1,400 yards away from the all-time rushing record.

Sport: Football

Age retired: 24

Years as a pro: 1

One thing to know: A first-round pick who put up solid numbers as a rookie, Borland famously retired after one season, citing concerns about brain injuries and trauma. He now works with former NFL players and military veterans who suffer from traumatic injuries.

Sport: Baseball

Age retired: 30

Years as a pro: 8

One thing to know: Nilsson put together the best season of his career in 1999, batting .309 with 21 homers and 62 RBIs, making an All-Star team, then hitting free agency. Instead of cashing in, he turned down big-money offers from MLB teams to return home to Australia to play in the 2000 Olympics. He played professional in Australia afterward, but never returned to MLB.

Sport: Football

Age retired: 31

Years as a pro: 8

One thing to know: Campbell began his career by leading the NFL in rushing three years in a row. Injuries played a part in a decline that resulted in a trade from the Houston Oilers to the New Orleans Saints in 1984. He retired in 1985, clearly no longer the same player.

Sport: Basketball

Age retired: 33

Years as a pro: 13

One thing to know: Thomas wasn't terribly young to retire, but not many greats go out at 33, either. Thomas' final season was the first and only time he didn't make an All-Star team, but he still averaged a solid 15 points and 7 assists per game. He tore his Achilles in his final game, which made his decision easier, though he later said he had made up his mind to retire before the injury occurred.

Sport: Football

Age retired: 32

Years as a pro: 10

One thing to know: Barber had one of his best seasons in 2006 before he decided to retire, rushing for over 1,600 yards, the third-best number of his career. He went into TV shortly after, and though he filed for reinstatement in 2011, he did not make a comeback.