LONDON (AP) Nico Rosberg stunned the world of Formula One and beyond by announcing his retirement on Friday at the age of 31, five days after winning his first drivers' championship.
Here are some other sports stars who retired at a young age:
BJORN BORG (TENNIS)
Borg retired at the beginning of 1983, aged just 26. Considered to be one of the greatest tennis players of all time, the Swede won Wimbledon five times in a row and also claimed six French Open titles.
Borg failed to win the US Open in 10 tries, losing four finals - 1976 and 1978 to Jimmy Connors, and 1980 and 1981 to McEnroe.
He played only one tournament in 1982, reaching the quarterfinals in Monte Carlo, before announcing he was quitting the game.
ROCKY MARCIANO (BOXING)
Marciano had been the world heavyweight champion for four years and won all 49 of his fights - 43 by knockout - when he retired in 1956 at the age of 32. The American wanted to spend more time with his family.
He died 13 years later in a plane crash.
Marciano, nicknamed the ''Brockton Blockbuster,'' remains the only heavyweight champion to retire undefeated.
MARCO VAN BASTEN (SOCCER)
Van Basten won three Ballon d'Or titles and two European Cups as well as the European Championship with the Netherlands in a glittering career that was cut short by injury at the age of 28.
He also helped Ajax to three Eredivisie titles and Milan to four Serie A trophies.
Milan's Champions League final defeat to Marseille in 1993 would be his final match due to persistent ankle problems that forced his retirement two years later.
Van Basten went on to a career in management, coaching Ajax and the Netherlands among others.
LORENA OCHOA (GOLF)
Ochoa was the top-ranked female player when she announced her retirement in 2010 at age 28, putting aside golf so she could start a family. Coming two years after the retirement of Annika Sorenstam at the age of 37, the LPGA was robbed of another of its biggest names.
Ochoa was probably the best-known athlete in Mexico who was not a soccer player, winning 27 LPGA titles and two majors - the Women's British Open in 2007 and the Kraft Nabisco Championship in 2008.
Ochoa gave birth to her first child 20 months after retiring.
JUSTINE HENIN (TENNIS)
The seven-time Grand Slam winner was still No. 1 in the WTA rankings when she shocked the world of tennis with the news of her retirement at age 25 in 2008.
She said she had lost the desire to train and wanted to rediscover the ''small pleasures'' of life.
Before Henin, no reigning No. 1 had retired from the women's game.
But the break did not last long. The 2004 Olympic champion returned 20 months later and reached the 2010 Australian Open final. She retired for good in January 2011 because of a lingering elbow injury.
MAGIC JOHNSON (BASKETBALL)
The Lakers point guard ended his career on Nov. 7, 1991 after he found out he was HIV positive.
One of the most gifted basketball players in the NBA with huge charisma, Johnson was 32 when he retired after 12 seasons with the Lakers, who drafted him in 1979.
Johnson did not stay away from the game long. He was the MVP of the 1992 All-Star game and won a gold medal at the Barcelona Olympics before briefly coaching the Lakers in 1994 and returning to the court for 32 games in 1996 before calling it quits for good.