Yao played just five games last season, and hasn’t been able to fully recover after having surgery in January to repair a stress fracture in his left foot. The veteran center informed the Rockets, the league office in New York and NBA China of his decision to leave the game within the past 48 hours, sources said.
Yao was set to become a free agent once the league’s lockout ends. He was once poised to become the league’s dominant big man, but lower-body injuries repeatedly sidelined him over the course of his career. He missed at least 25 games in five of the past six seasons.
Yao, who was the top overall pick of the 2002 NBA draft, finishes his career with per-game averages of 19.0 points, 9.3 rebounds and 1.9 blocked shots.
Yao had hoped the surgery would allow him to return for the 2011-12 season – and said he'd like to return to the Rockets. But he also conceded that he may have already played his final game.
Yao appeared to be nearing his peak when he averaged 19.7 points and 9.9 rebounds over 77 games in the 2008-09 season. But after helping lead the Rockets past the Portland Trail Blazers in the first round of the playoffs, he broke his left foot in a tough series with the Los Angeles Lakers. Yao underwent a complicated surgery – similar to the one that saved the career of Miami Heat center Zydrunas Ilgauskas – and missed all of the next season. He never truly regained his form, lasting just five games last season before suffering another stress fracture.
"A career is almost like a car race," Yao told Yahoo! Sports' Marc Spears in March 2010. "You push the gas to see how good the car is. It takes time to get from zero to 100 miles [per hour]. This is the same thing. You don’t want to hit a hard brake. This is a hard brake for me. If you want me to start up again, you probably need me to take some time."
The injuries kept Yao from ever fully reaching his potential – and prevented the Rockets from continuing to build off their success in 2009.
"If he was never injured, he would have been one of the greatest centers ever," said Rafer Alston, a point guard for the Rockets from 2005-09. "You can't guard him. You had to foul him. He's 7-6, so he has a height advantage. He had the jump hook over the shoulder.
"If he was healthy we would have gone far. He would have been one of the greatest centers of all-time if he was healthy."
The Rockets acquired Tracy McGrady prior to Yao's third season in the league, hoping to give their center a superstar complement. Injuries to both, however, limited the Rockets to just one playoff series victory in their tenure together.
"I feel very honored to have not only played with one of the greatest big men in our league, but to also call him my friend," McGrady said. "I wish Yao continued success in all his ventures in life."
The Rockets traded McGrady midway through the 2009-10 season after acquiring Kevin Martin. Martin played just five games with Yao before Yao's latest injury.
"I wanted to have an opportunity like Steve Francis and T-Mac [to play with Yao], but, unfortunately, that won't happen," Martin said.
Yao's work ethic and sense of humor endeared him to teammates and opponents alike.
"Yao was one of the greatest people on earth, so it wasn't selfish [for him to retire]," Alston said. "He was one of the hardest-working guys. He was about the team.
"He didn't like the spotlight. He just liked being around the guys."
The NBA loses one of its few remaining star centers with Yao's retirement. Shaquille O'Neal, a rival and friend of Yao's, ended his 19-season career in June.
"Yao will definitely be missed," O'Neal said in an email. "He is in my mind one of the best centers ever to play. He is the one of the greatest athletes ever to come out of China, and I will miss him."
Rockets forward Chuck Hayes is in China as part of a promotional tour for a Chinese shoe company. He had lunch with Yao last week, but they didn't discuss Yao's health or future. He heard about Yao's plans to retire when he awoke Saturday morning.
Hayes is one of many Rockets who have benefited from Yao increasing the NBA's popularity in China.
"What has he done for the game? Because of him I'm in China now doing promos," Hayes said. "He will still be involved in the NBA. He's a global icon."
Yahoo! Sports' NBA reporter Marc J. Spears contributed to this story.
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