USC sophomore quarterback JT Daniels will miss the rest of the season after tearing the ACL and meniscus in his right knee during Saturday's 31-23 win against Fresno State, coach Clay Helton said Sunday.

Daniels will undergo surgery in the next few weeks, Helton said, and will be eligible to use the season as a redshirt year.

True freshman Kedon Slovis, who went 6-of-8 for 57 yards with an interception in relief against Fresno State, will start on Saturday against No. 25 Stanford in the Pac-12 opener for both teams. Slovis beat out redshirt junior Matt Fink and redshirt sophomore Jack Sears to win the No. 2 job during training camp.

"We've got all the confidence in the world in his ability," Helton said of Slovis. "We'll look forward to watching him play on Saturday."

Slovis enrolled at USC prior to spring practice following his senior year at Desert Mountain High in Scottsdale, Arizona, where he was named a USA Today All-Arizona honorable mention after throwing for 2,542 yards with 18 touchdowns and six interceptions in 2018.

In his first three years at USC, Fink completed 13 of 18 passes for 89 yards with one touchdown. He redshirted in 2016 before backing up Sam Darnold in 2017 and Daniels last year.

Fink entered the transfer portal in April to seek out a destination where he could play in 2019 before deciding to return. Sears entered the transfer portal last week after finishing fourth in the competition. He is no longer with the team.

The status of Stanford quarterback K.J. Costello is also in question after he left Saturday's win against Northwestern in the second quarter after receiving a hit to the head. If he's unable to play, Davis Mills will start for the Cardinal.