The Rockets lead the series 3-2.
The 6-foot-5 Wafer has been a key reserve for Houston in the series, averaging 10.6 points and 1.2 assists. Wafer averaged 9.7 points during the regular season and was the team's second-best 3-point shooter (39 percent).
Wafer played 16 minutes in Portland's 88-77 victory in Game 5 on Tuesday. He underwent X-ray and MRI exams on Wednesday that revealed the bulging disk. He's listed as day to day.