SAN FRANCISCO — Warriors star Jimmy Butler is out for Game 3 of Golden State’s first-round playoff series against the Houston Rockets on Saturday night after injuring his pelvis and suffering a deep gluteal muscle contusion in a hard fall during Game 2.Butler had been set to go through his pregame routine, which he does out of sight on the team’s practice court and not the playing floor before games at Chase Center. He had an MRI exam Thursday in the Bay Area a day after he was hurt in Houston. The best-of-seven series is tied at one game apiece with the next two games on the Warriors’ home floor. Game 4 is Monday night.Butler went down hard when fouled by Amen Thompson late in the first quarter and then missed the rest of the Warriors’ 109-94 Game 2 loss on Wednesday night.Butler tried to secure a rebound when Thompson undercut him and sent the Warriors star’s feet high into the air so he came down straight onto his tailbone. Both players thudded to the floor with the collision and Butler grimaced in pain grabbing at his backside. He stayed in briefly to shoot two free throws before going to the locker room.Kerr was prepared for any scenario, even having Butler in a limited role.“That’s Plan C. We’ve got A and B lined up,” Warriors coach Steve Kerr said. “You saw Plan C the other night. When somebody goes out in the …