It looked like a harmless stumble at the end of an ordinary play, a moment that happens dozens of times in an NBA game but one that could cause a serious setback to the Raptors.

Kyle Lowry, who had been the team's most consistent player and its leader, hobbled off the Chesapeake Energy Arena floor, unable to put any weight on an injured right ankle late in the second quarter of Tuesday's 108-88 drubbing administered by the Oklahoma City Thunder.

Lowry, who went into the game averaging more than 23 points and seven assists per game, appeared to step on the foot of Oklahoma City's Serge Ibaka when the two got tangled up after a Raptors basket with about 90 seconds left in second quarter.

He immediately crumpled to the floor under the basket, hammering the floor repeatedly with his fist, in obvious pain.

Team officials said he suffered a right ankle sprain. Lowry missed the remainder of the game and will be re-evaluated when the team gets to Dallas for a Wednesday night game.

Any extended absence of Lowry will be a devastating blow to the Raptors, who fell to 1-3 with Tuesday's loss.

Despite still getting fully acclimated to his new teammates, the 26-year-old guard has made an imprint on the team at both ends of the floor.

He has provided a much-needed dose of toughness and confidence defensively and offensively, and he's meshed wonderfully with shooting guard DeMar DeRozan to give Toronto a potent duo.

"I think my teammates have done a great job of letting me understand that, 'OK, Kyle, you can go a do a few things, be more aggressive,' but I always want my teammates to get theirs before I even attempt to get mine," said Lowry, acquired in the off-season in a trade with the Houston Rockets.

The Raptors do have a qualified backup in veteran Jose Calderon, who had been the team's starter until the acquisition of Lowry.