The Rockets want Yao to strengthen the muscles in his left ankle, which he injured on Nov. 10, the Houston Chronicle reported.
Yao suffered what was initially diagnosed as a mild ankle sprain in a game against the Washington Wizards. About a week later, it was announced he would miss another two weeks.
The Rockets have been closely monitoring Yao's minutes this season. He sat out all of last season following surgery to repair his broken left foot.
Yao said he "won't push" the team's medical and training staff and knows they're trying to get him back on the floor, according to the Chronicle. But Yao says he's ready.
"I'm waiting for the green light," Yao said, according to the report. "When? I don't know. I feel better. It still has some weakness. I'm just not ready to sit out for almost 20 games, particularly when I feel I'm OK. I know when I was in the walking boot, on the crutches, OK, I understand."
Has Yao told the team how he's feeling?
"I tell them every day," he said with a laugh, according to the Chronicle.
Rockets coach Rick Adelman said he has not been told when the team will clear Yao to practice, according to the report.
Information from The Associated Press was used in this report.