JJ McCarthy has a torn meniscus in his right knee, Minnesota Vikings head coach Kevin O’Connell told reporters on Tuesday.

McCarthy started to complain of soreness in his knee over the weekend. He underwent an MRI on Monday and was held out of the team’s evening practice. He is expected to undergo surgery to determine the extent of the injury and the amount of time he’ll need to miss.

McCarthy made his debut on Saturday in Minnesota’s 24-23 preseason victory over the Las Vegas Raiders. He completed 11 of his 17 passes for 188 yards and 2 touchdowns. He had scoring strikes of 45 and 33 yards, but he also threw an interception early on.

O’Connell called McCarthy’s performance a “glorified, singular step in the process.” He added that Minnesota had a plan for McCarthy throughout training camp. The Vikings’ head coach also said McCarthy was removed from Saturday’s game because he’d hit his scheduled snap count.

There didn’t appear to be any sign of injury during or after the game.

“Out of precaution, we’re going to continue an evaluation on him and get some more testing done,” O’Connell said on Monday. “A very important player, obviously, so we want to make sure we’re smart before he participates, making sure we have a good understanding of where he’s at.”

Though he was taken with the 10th overall pick in this year’s NFL Draft, McCarthy was not expected to open the season as the starter in Minnesota. He’d spent most of camp prior to Saturday working with the second team. Veteran quarterback Sam Darnold started the preseason opener for the Vikings, completing 4 of his 8 passes for 59 yards.

Shortly after the NFL Draft, sportsbooks had installed McCarthy as one of the favorites to lead all rookies in passing yards in 2024. He was priced at +1100 (bet365) to win the NFL’s Offensive Rookie of the Year award.