The Portland Trail Blazers are waiting to discover the extent of  CJ McCollum's knee injury that occurred in their 108-103 defeat to the San Antonio Spurs on Saturday.

McCollum will undergo an MRI scan when he returns to Portland on Sunday after he was hurt in the third quarter at the AT&T Center.

X-rays taken after the game came back negative, but McCollum has no idea how serious his injury is with the NBA play-offs on the horizon.

"I don't have a lot of information besides it's painful," he said. "I didn't hear anything pop. It was just an immediate discomfort and pain. It was an uncomfortable feeling. You never want to leave the court like that, but it happens."

McCollum added: "I went up for a layup, a left-hand layup, and the big fella [Jakob Poeltl] blocked it. I landed on my foot, kind of trapped my foot on the ground, felt my knee kind of twist. I was in pain. It hurts. You never want to get hurt, man. Not ever, especially at this point in the season.

"There's nothing I can do about it but rehab and see what they say. I can walk, but I'm not sure what the extent of it is. Obviously, on the replay it's hard to kind of see it because my foot is trapped and his body is there.

"But there's some discomfort, some pain in certain areas. So we'll see what happens. It's definitely around my knee, but I don't know the extent of it. I don't know if it's lateral. I don't know. I just know that it's not normal."