Is Vikings QB Sam Darnold injured? This is what he and the team say.

MINNEAPOLIS — Vikings fans held their breath on Sunday when quarterback Sam Darnold appeared to be injured and left the field. They breathed a sigh of relief when he returned after missing a game, but it's unclear how serious the injury is.

Although Darnold finished the game, both he and head coach Kevin O'Connell stated after the game that further testing was needed.

“We'll evaluate it, we'll look at it, but it felt good enough to get back in the game,” Darnold said.

“He got a little rolled on the penalty, that was pretty bad for him. He checked out and came back into the game,” O'Connell said. “We'll do an evaluation to rule everything out, but I'm proud of Sam coming back into the game and helping us get down the field.”

When asked if his injury would prevent him from practicing this week or playing in Sunday's game against the Green Bay Packers, Darnold said, “I'm not sure.”

O'Connell is expected to speak to the media on Monday afternoon and could provide an update then.

Darnold's injury occurred late in the third quarter when former Viking player Danielle Hunter hit him low. Hunter received a roughness penalty on the play.

“Hunter is obviously a great player and definitely not an unfair player,” Darnold said after the game.

Backup quarterback Nick Mullens came in for one play while Darnold had his left knee checked out. Darnold then jogged back onto the field, buoyed by the ovation from the U.S. Bank Stadium crowd.

“The reaction from the fans meant everything to me,” Darnold said. “Not only that, but my entire time here in Minnesota with the fans has been amazing.”

Darnold's solid play was an important part of the Vikings' 3-0 start. Victory on Sunday against the Houston TexansHe threw four touchdowns and no interceptions. He is first in the league in touchdown passes, second in passer rating and fourth in adjusted net yards per attempt and QBR.

The Vikings have already lost a quarterback for this season. Rookie JJ McCarthy a meniscus tear in his first warm-up game and was placed on the injured list after a successful operation. In addition to Mullens, the Vikings also have the experienced Brett Rypien in the squad.