USC junior forward Ari Stewart will miss up to three weeks with a broken left thumb.

The injury occurred midway through the second half of USC's 71-60 win over Washington Sunday night at the Galen Center. It is unclear if it happened when Stewart fouled Scott Suggs on a reverse layup or sometime during USC's subsequent possession when Stewart missed his fourth 3-pointer of the game.

After the shot, Stewart immediately began holding his left hand close to his body and motioned for the USC bench. When a foul by James Blasczyk stopped play with 8:10 remaining, Stewart was removed from the game and did not return.

According to teammates, Stewart thought he had broke his thumb, but initial reports were that Stewart had a left thumb sprain.

X-rays later confirmed the break and Monday morning the school announced that Stewart would likely miss up to three weeks with the broken bone.

The 6-foot-7 Stewart has seen a resurgence in playing time since Bob Cantu took over as interim head coach. In nine games prior to head coach Kevin O'Neill's firing, Stewart had played twice for a total of 13 minutes.

Under Cantu, Stewart has been an essential bench contributor as a swingman off the bench. He has averaged 13.3 minutes, scoring 4.4 points per game, including a USC career-high 11 points Thursday against Washington State. He has also contributed three rebounds per game and five blocks in the last seven games.

Without Stewart, Cantu may turn to seldom-used fifth-year senior transfer Renaldo Woolridge. At 6-foot-9, Woolridge has a similar game to Stewart. He can shoot the outside shot and use his length to defend the 2 through 5 positions on the court.

If Stewart is out three weeks, he will miss five games -- all against teams USC is tied with or trailing in the conference standings. He would return in time for the final road trip of the regular season before the Pac-12 Tournament in Las Vegas.