The Rockets acquired the rights to the 6-foot-11 Andersen in a trade with Atlanta on July 14. Houston scrambled to find a center after announcing in June that Yao was out indefinitely with a hairline fracture in his left foot.
Yao announced last month that he would have surgery to repair the injury, a decision that will likely keep him out all of next season. The seven-time All-Star underwent the procedure the following week.
Andersen was a second-round draft choice of the Hawks in 2002. He has spent his career in his native Australia and in Europe, most recently in the Spanish League with FC Barcelona, where he averaged 11.1 points and 4.1 rebounds last season.