It was the first missed game of the season for Roy, who averages 18.1 points.
Roy, in his fifth season out of Washington, left Saturday's game at New Orleans after playing only 22 minutes, and scoring two points on 1-of-7 shooting.
Wesley Matthews, in his second season out of Marquette, replaced Roy in the starting lineup and scored a career-high 30 points in Portland's 100-99 victory over the Grizzlies.
Last week, Roy said he would have to limit his playing time, the result of several injuries.
In April, Roy underwent surgery on his right knee, but was able to play eight days later in the playoffs against the Phoenix Suns.
"I would love to play more minutes and have a much better body," Roy said last Tuesday, "but it's just not the case, so I have to try and make the most of what it is."
Information from The Associated Press was used in this report.