PORTLAND (Reuters) - Portland Trail Blazers All-Star guard Brandon Roy will undergo arthroscopic surgery on both knees next week in hopes of easing a painful problem that has sidelined him for the past month.

The injury-hit Trail Blazers said on their website (www.nba.com/blazers) there was no timetable for his return but the team hoped he would be back this season.

Roy, 26, has missed 16 games including 13 in a row since December 17 with a sore left knee.

"I'm trying to do the best thing I can to get back on the floor," the 2007 NBA rookie of the year told the website. "We've been able to get a number of different opinions and it's something we've decided."

The Trail Blazers, 20-19 and mired in fourth place in the Northwest Division, have already lost centers Greg Oden and Jeff Pendergraph for the season because of knee surgeries.

The team is hoping the procedure, to remove dead tissue, will smooth out the bone surfaces and tissue fragments in Roy's knees so the three time All-Star can play with less or no pain.

Roy led the Portland scoring in the past three seasons. He started 23 games this season, averaging 16.6 points, and has a career average of 19.9 points.

(Reporting by Gene Cherry in Salvo, North Carolina; Editing by John Mehaffey)