On Saturday, Vikings quarterback J.J. McCarthy directed three touchdown drives in a promising preseason debut that filled the fanbase with optimism. On Tuesday morning, Vikings coach Kevin O'Connell announced news that meant the game would be the rookie's only one for a while.

McCarthy will need surgery for a meniscus tear in his right knee that he sustained during the Vikings' 24-23 win over the Raiders on Saturday, O'Connell said Tuesday morning. The quarterback came to the team facility Monday reporting some knee soreness; though the Vikings hoped it was just lingering soreness from the game, they scheduled an MRI for McCarthy on Monday night, and the results showed the tear.

The rookie from Michigan likely will undergo surgery this week, and O'Connell said McCarthy will not travel with the team to Cleveland, where the Vikings have joint practices scheduled with the Browns on Wednesday and Thursday before Saturday's preseason game. The team had planned for McCarthy, the 10th pick in the draft, to get more first-team work in the joint practices than he'd had all training camp. Instead, the Vikings will have to wait for the operation to determine how soon McCarthy could return to the field.

"Hopefully we're having a shorter timeline than a longer timeline," O'Connell said. "But the most important thing right now is making sure, from a medical standpoint, that we've identified the potential severity when we do that procedure."

If the tear is small enough that McCarthy would only require a trim to the damaged cartilage, he could return in several weeks. Players often opt for a full meniscus repair, though, since the surgery typically yields better long-term results. The return from a full meniscus repair can take several months; if McCarthy needed a full repair, he'd likely miss most or all of his rookie season.

"What's best for the long-term health of J.J. McCarthy will be the priority," O'Connell said, adding he won't be part of what he called "totally a medical decision."

McCarthy played 30 snaps in the Vikings' preseason opener against the Raiders, completing 11 of his 18 passes for 188 yards, two touchdowns and an interception while scrambling twice for 18 yards. O'Connell said he took McCarthy out because he'd reached the number of snaps the Vikings planned for him, adding the quarterback could have continued to play with the injury.

McCarthy posted on the X platform (@jjmccarthy09), "Love you Viking nation. I'll be back in no time. Amor fati." Amor fati or "love of fate" means generally accepting one's fate; the motto is common in Stoic philosophy, was popularized by Friedrich Nietzsche and might have proved useful for Vikings fans on Tuesday.

O'Connell said he wasn't sure which play caused McCarthy's injury. "Thinking back and having watched it a few more times, I'd just be speculating because there wasn't a moment where it was noticeable," he said.

The Vikings had planned a methodical course of development for McCarthy, making Sam Darnold the No. 1 quarterback and saying the rookie wouldn't start until he showed he was ready. But McCarthy's debut on Saturday stoked optimism for the fanbase, as he recovered from an early interception to throw two long touchdowns and convert several key third downs.

"We talk a lot about this development plan," O'Connell said Monday. "A huge part of it is, these real game reps where there's coaches on the sideline, it's just them and the defense and the officials out there. I want to see him continue to progress, but clearly everybody can see the arm talent. I just love seeing him come right back after the interception and still be aggressive, still stay true to footwork, timing, rhythm, where his eyes should be. So there was a lot of positives with J.J.'s performance tonight, and a lot of areas where we'll be able to hit the ground running when these guys are back."

That work will have to continue off the field for now, as the Vikings learn more about how long they will be without the rookie. The injury is the Vikings' second major loss at quarterback in the past 10 months, after Kirk Cousins' torn Achilles last October; especially if McCarthy is out for most of the season, the injury could have implications for the Vikings' transition plan at quarterback.

For now, they will move forward with Darnold, who went 4-for-8 for 59 yards on Saturday, firmly in the top job. "My confidence in Sam is very, very high," O'Connell said.