The Spurs could be without Victor Wembanyama for multiple games after he entered the NBA’s concussion protocol following a hard fall in the second period that forced him from Game 2 of the team’s first-round playoff series with Portland.

Without their star player, the Spurs fell 106-103 on Tuesday night after claiming a 111-98 win in the opener on Sunday.

“I just know he has a concussion and he’s in the protocol,” Spurs coach Mitch Johnson said. “We’ll obviously take the proper and appropriate steps.”

Asked if the league’s defensive player of the year was being evaluated for anything beyond a concussion, Johnson quickly said, “No.”

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

“We all got to step up,” Spurs forward Devin Vassell said. “We know what Vic brings to the table and we’ve played without him a couple of games this year. That’s huge void to fill. We can’t get bogged down by it. We just go to go day by way, watch the film, adjust and get ready for this next game because it’s going to be a dog fight.”

Wembanyama landed hard on his chin after getting fouled by Jrue Holiday in the paint while driving to the basket with 8:57 left in the first half. The 22-year-old Frenchman appeared to be dazed after the fall and was on the court for about 30 seconds before sitting up for about a minute while being checked on by his teammates and athletic trainer Will Sevening.

“I got the foul call,” Holiday said. “I didn’t think I touched him, but I don’t really know. After they called the foul, I went to complain to the ref. I didn’t really see (Wembanyama go down).”

Spurs coach Mitch Johnson called a timeout before Wembanyama got to his feet under his own power and headed to the locker room with Sevening and Spurs general manager Brian Wright trailing behind.

Shortly after Sevening and Wright left the locker room, the Spurs announced Wembanyama was out for the rest of the game.

The Spurs trailed 34-32 when Wembanyama suffered the injury. Wembanyama finished with five points and four rebounds in 12 minutes after scoring 35 points in Sunday’s 111-98 win in the best-of-seven first-round Western Conference series.

The Spurs did not have a timeline for Wembanyama’s return. Per the NBA’s concussion protocol, if a player is diagnosed with a concussion, he cannot return to participating for at least 48 hours, including the date of diagnosis, and until after he completes the required  return-to-participation process.

NBA players typically miss at least a week after suffering a concussion. Game 5, if necessary, is set for April 28 at the Frost Bank Center.

Game 3 is scheduled for 9:30 p.m. Friday in Portland. Game 4 is set for 2:30 p.m. Sunday.

The Spurs won the season series against the Trail Blazers 2-1 with Wembanyama sitting out all three games, but his loss would be a severe blow to a team with championship aspirations.