The procedure, which took place Thursday, lasted 20 minutes, according to The (Portland) Oregonian. The team physician, Don Roberts, performed the arthroscopy, during which he took out a small flap of cartilage.
Training camp is seven weeks away; the Blazers are anticipating Roy could be back in four to eight weeks, in time for the Oct. 28 season opener.
"We are very relieved today," general manager Kevin Pritchard said in The Oregonian. "I think we all have a collective sigh of relief, because with these knee injuries, a lot can happen, and you are talking about the career of a young man who has put his face on this organization, and [a player] who we care deeply about."
Roy is part of a young nucleus for the up-and-coming Blazers. The 2006-07 Rookie of the Year has averaged 18.1 points, 5.0 assists and 4.6 rebounds in two years in the league.
"We were all walking on eggshells around here," Pritchard said in The Oregonian. "I can tell you this: I didn't sleep a whole lot last night . . . and I feel very, very good about where we are today. We are in great position to have him ready by the regular season."
Information from The Associated Press was used in this report.