The team said Wednesday that Howard had a bone marrow aspirate injection and would begin rehabilitation immediately. The team said he will be re-evaluated in approximately four weeks, but it did not offer a time for him to return to playing.
"It's really a shot," said Dr. Walt Lowe, of the Memorial Hermann Sports Medicine Institute. Lowe performed the procedure. "It's not a surgical procedure. It's a 20-minute deal. I don't think it's a very big deal," Lowe told FOX26 Sports on Wednesday.
"I would certainly expect him before the playoffs," Lowe said. "I really expect him to recover and play again this season."
Howard last played Jan. 23, when he left a game at Phoenix against the Suns with a sprained right ankle. He later reported swelling in his right knee.
At the time he was injured, Howard was second on the Rockets in scoring with 16.7 points per game and led the team with 11.2 rebounds a game. The Rockets have gone 3-1 since then heading into Wednesday night's game against Chicago.
Information from The Associated Press was included in this report.