The Clippers-Rockets game in Houston on Saturday night could be a second-round playoff preview, as the teams enter the game as the third- and fourth-place teams in the West.
Howard declared himself out as he walked off the court after shootaround, which he went through in slippers, according to Markazi.
The 28-year-old, who is averaging 18.5 points and 12.3 rebounds per game this season, missed three games with the injury. He returned for two games, and put up good numbers in both, but struggled in the second half of Thursday's win over the 76ers.
He had a procedure to remove a cyst from the ankle on Tuesday.
The Rockets, who have won five in a row, will also be without Patrick Beverley, whose torn right meniscus was discovered on Friday. SI WIRE: Carmelo Anthony: Making playoffs would salvage first-ever losing season