Howard missed three games with the injury and struggled in the second half of Thursday's game, his second game back after missing three games after he had a procedure to remove a cyst from the ankle Tuesday.
Howard went through shootaround on Saturday in slippers and ruled himself out as he walked off the court.
"I talked to Dwight, and he won't play tonight," Rockets coach Kevin McHale said.
When asked when he would play, McHale said, "I'll let you know tomorrow."
The Rockets already are without Patrick Beverley, who had an MRI on Friday that revealed a torn meniscus in his right knee.