The 6-foot-7 Brockman, Washington's career leader in rebounds (1,283), was a second-round pick by Portland (38th overall) in 2009.
Brockman was hurt Monday while working with an elastic band used for stretching muscles. The band apparently slipped off his foot and the recoil hit Brockman's right eye.
Brockman was treated at a hospital and released Thursday. The injury did not require surgery, and the team said Brockman will be monitored daily by team doctors. The Rockets set no timetable for his return to basketball activities.