Miller Moss hadn't gotten any reps in the live team periods in recent weeks, since being named USC's No. 3 quarterback, so he didn't know quite what to expect at the start of this week in taking over as the Trojans' backup quarterback with fellow freshman Jaxson Dart sidelined.

"I wasn't sure how it was going to go, but I felt good out there, I felt like I operated," he said Tuesday.

Moss is now just one hard hit on starter Kedon Slovis from being pressed into action, and as the last few years have taught USC fans, that is always a possibility.

Slovis was forced out of the game last Saturday at Washington State with a neck injury after getting clobbered on a sack to end USC's first possession. Dart came in to play the starring role, passing for 391 yards, 4 touchdowns and 2 interceptions in that 45-14 win, but he sustained a torn meniscus in the process and had surgery earlier this week.

So for the foreseeable future, the Trojans are down to just two available scholarship quarterbacks.

"I don't think [things] change very much, honestly. I mean, guys go down, it's part of football. You know what I mean, it's just my job to be prepared, and I've prepared like I was a starter each week so nothing really changes for me," Moss said.

Last week, when Slovis was knocked out of the game, Moss readied himself on the sideline in case he would be needed.

"First, I was like I need to find someone to chart the coverages, because that's what I was doing," he joked.

And Moss would indeed get in the game briefly when Dart's helmet came off and he was forced to come off the field for a play, per rule. Moss stepped in and handed the ball off, officially making his Trojans debut.

"It was awesome. I wanted to stay in there. It was really cool to get on the field. I haven't been on the field in almost two years, so that was really cool. It was the first time I've really heard crowd noise before," he said.

Moss, from local Bishop Alemany High School, and Dart both arrived at USC in January as highly-touted four-star freshmen. They competed through the spring and fall camp for the backup job, which Dart won.

When that decision came down, Moss had a request for former coach Clay Helton -- he would rather be the scout team quarterback at least doing something against the defense every day than to stand on the sideline.

"That's probably the best defense I'll go against or will go against all year, so I think that just makes it better. That was something when I got named the 3 that I talked to Coach Helton about, because I guess that wasn't going to happen," Moss said. "I asked him, I'd much rather get live reps than just stand over there. So that was something that's helped me."

In the meantime, Moss has also put in some extra film work with USC's defensive coaches to glean more perspective on what is happening across the line of scrimmage.

"I just started watching film with some of the defensive coaches just because I feel like it's important to understand football from both sides, understand what some of the defensive guys are thinking and what their responsibilities are. I think that will just help me more on the offensive side," he said.

In 2018, USC got down to its third quarterback after starter JT Daniels was concussed and backup Matt Fink injured his ribs in relief. That left No. 3 QB Jack Sears to start the next game.

In 2019, it happened again as Daniels sustained a season-ending injury in Week 1, and Slovis later missed most of two games with a concussion, forcing Fink into extended action.

The Trojans made it through mostly unscathed in their shortened six-game season last year, as Slovis avoided injury until the final offensive play of the season, hurting his shoulder on a sack in the Pac-12 championship game.

But any game could be Moss' turn.

"I think the only thing that's constant in football is change, so I've just got to always be ready when my number's called," he said.