SAN ANTONIO — San Antonio Spurs star Victor Wembanyama was placed in the NBA's concussion protocol after tumbling face-first to the court in the second quarter of Tuesday night's playoff loss to Portland.

"He has a concussion. He's in the protocol," Spurs coach Mitch Johnson said after San Antonio fell 106-103 to even the Western Conference first-round series at one game apiece. "We'll take the proper and appropriate steps."

Any extended absence by Wembanyama would be a massive blow to San Antonio, which finished with the league's second-best record behind the versatile 7-foot-4 (about 2.24 meters) center from France.

Under league guidelines, a player in the concussion protocol must have at least 48 hours of inactivity and recovery and then hit several benchmarks without symptoms before being cleared to play. A player must undergo neurological testing and receive a final clearance from a team doctor in consultation with the league's concussion protocol director.

Game 3 is Friday in Portland. It seems improbable that Wembanyama would be cleared by then, but Johnson wouldn't speculate about his status. "The protocol is the protocol," Johnson said.

"We'll just follow it, as everyone else does, and plan accordingly."

The Spurs went 12-6 during the regular season without Wembanyama.

"We've all got to step up," Spurs guard Devin Vassell said. "We know what Vic brings to the table. We've played without him for a couple games this year. It's going to be next man up. Everybody's going to have to step up. That's a huge void to fill. We can't get bogged down by it."

Wembanyama was fouled by Jrue Holiday after he spun around the Trail Blazers point guard in the paint. He was not able to brace himself on the fall, and his jaw hit the court with 8:57 remaining in the second quarter.

Wembanyama remained prone on the court for about 30 seconds before rising to a seated position for about a minute and speaking to teammate Stephon Castle.

Johnson called a timeout to check on Wembanyama, who immediately ran through the tunnel after getting to his feet.

Wembanyama had five points, four rebounds, one blocked shot and one assist in 12 minutes. Veteran Luke Kornet replaced Wembanyama and started the second half at center, finishing with 10 points and nine rebounds in 28 minutes.

"It was scary. I saw the images. It was not good," Trail Blazers coach Tiago Splitter said of the play where Wembanyama got hurt.

"With him out, Kornet, I think he did a tremendous job. We still have to figure out how to play better when Kornet is on the court."

San Antonio is in the playoffs for the first time since 2019 and beat Portland in Game 1 of the Western Conference first-round series behind 35 points from Wembanyama. Without him, the Spurs blew a 14-point fourth-quarter lead in the playoffs for the first time since 2003, a span of 76 games.

On Monday, Wembanyama became the unanimous winner of the NBA's Defensive Player of the Year award. He averaged 25 points, 11.5 rebounds and a league-best 3.1 blocks this season.

Vassell said he didn't have a chance to talk with Wembanyama immediately after the game.

"Our prayers are with him," Vassell said. "We just want him to be good."

Scoot Henderson scored 31 points for the Blazers. Holiday had 16 points and nine assists, Deni Avdija scored 14 and Robert Williams III finished with 11.

Castle led the Spurs with 18 points, De'Aaron Fox scored 17 and Vassell had 16 points and 12 rebounds.