Yao underwent surgery on the stress fracture in his left foot earlier in the week, which the Rockets described as successful.
The Chinese sporting icon is expected to have to wait up to four months before beginning rehabilitation, leaving little over a month to prepare for the Games in his home country which begin on August 8.
The injury has caused plenty of stress in China amid fears that the key to the nation's basketball medal hopes may not be at his best during the highly anticipated Olympics.
"So far, the operation has been a great success... "
China has also been promoting the globally popular Yao as one of the key faces of the 2008 Games.
"So far, the operation has been a great success and soon I will begin physical therapy and rehabilitation," Yao said in his letter.
Fans show support
The 27-year-old added that his confidence was buoyed by the timely discovery of the injury and the top-quality care he has been provided by his NBA club.
The unassuming Yao, who stands at 2.29m tall, also thanked Chinese fans for their support, calling it a crucial part of his success.
"You have not hesitated to give me tremendous support and encouragement, constantly driving me forward," said Yao.
"Amid this, I want to say to everyone: thanks for your concern and support."
Yao had been enjoying the best year of his NBA career when the injury was discovered, as he helped the Rockets to a winning streak that has since stretched to a team-record 16 games.