Rivers said the Celtics showed interest in Asik, but the asking price was too high. He signed a three-year, $25 million back-loaded deal with Houston . . . Paul Pierce laughed when told Dallas coach Rick Carlisle said he looks forward to when the Celtics retire his No. 34. “I’ll be happy to be there,” he said . . . Rockets guard Toney Douglas is 17 for his past 31 from the 3-point line after hitting 2 of 3 Friday night. He was acquired in an offseason trade with the Knicks . . . Avery Bradley is on the trip and took shots during shootaround but Rivers said he had no idea when Bradley would return . . . Royce White, whom the Celtics considered drafting before the Rockets took him 16th overall, remains out after a dispute with the team over his anxiety disorder treatment.