Vikings coach Mike Zimmer is optimistic about the health of starting cornerback Xavier Rhodes, who suffered a concussion on Sunday.

Rhodes collided with safety Andrew Sendejo late in the second quarter of Sunday’s 31-14 victory over the San Diego Chargers. Rhodes’ neck snapped back, and he was briefly motionless and face down in the turf before being helped off the field.

Zimmer said Rhodes’ injury was limited to a concussion.

“Actually he’s feeling great,” Zimmer said Monday. “He’s already passed one test. I think we should be good to go.

“Xav is pretty tough … so I knew he’d be all right.”

Zimmer also said he assumes wide receiver Charles Johnson should be ready to go. He left Sunday’s game in the first quarter because of injured ribs. He returned but quickly came out because he couldn’t twist well enough.

The Vikings lost three starters — Rhodes, Johnson and Sendejo (leg) — and reserve defensive end Justin Trattou (ankle) to injuries in Sunday’s victory.

Waynes steps in

If Rhodes isn’t ready to go for Sunday’s game against Peyton Manning and the Broncos in Denver, the Vikings appear to have a good backup option.

Rookie cornerback Trae Waynes took 41 defensive snaps in the second half on Sunday. He made four tackles, assisted on a fifth and had one deflection.

The Vikings’ 2015 first-round draft pick (11th overall) played only on special teams in the season’s first two games.

“I thought he did well. I’ve been saying all along that he continues to get better every week,” Zimmer said. “I felt like there was going to be an opportunity in the game this week, that he may end up playing. I didn’t expect it under those circumstances, but he did well for his first real test under fire.”

San Diego quarterback Philip Rivers tested Waynes, but Waynes almost had an interception. He said he expects veteran QBs to test him if he continues to get more playing time.

“It was really important to [make an impact right away]. They say veteran quarterbacks are going to go against rookies until you stand up for yourself, and that’s what I tried to do,” Waynes said.

Veteran cornerback Captain Munnerlyn liked what he saw from the rookie in Monday’s film session.

“He did a great job,” Munnerlyn said. “He came and competed. That’s all you can ask for from young guys. … He had that swagger on himself [Sunday].”

Into thin air

Zimmer isn’t concerned about the high altitude in Denver, or how it will affect player rotations.

“As I told my team, scientifically when you’re out there for 24 hours it really is no factor,” he said. “We want to continue to use our team that way. Guys that earn the right to play, that deserve to play, continue to play because we want to be a deep team.”

The Vikings defense had 18 players take at least 19 snaps.

“We’ve got a lot of depth on this team,” Munnerlyn said. “We can go out there and compete with the best of them. … We’re just trying to stay healthy.”

Peyton’s place

Manning was a hot talking point around Winter Park on Monday. The Vikings face the five-time league MVP and 14-time Pro Bowl selection, and he’s a guy Vikings safety Harrison Smith has been following since Smith was a young boy growing up in Knoxville, Tenn. Manning was a college standout at Tennessee.

“I’ve obviously seen him play a lot,” Smith said. “But watching him on film, I’ll just try to see what they’re doing. He knows how to get them in the best play to defeat what we’re doing on defense by making his checks and stuff at the line. So that’s one thing you’ve just got to be aware of.

“He’s been doing this for a long time. He’s going to be a Hall of Famer. So he’s a great quarterback. As a defensive back, you always want to play against the best.”