Clay Helton has declined to provide many specifics about exactly how compromised USC's roster will be Sunday vs. Washington State, after having four players test positive for COVID-19 last week and seven others placed in quarantine after the contract tracing process.

But the question had to be asked anyway -- how many of the Trojans' standard five starting offensive linemen does he expect to be available vs. the Cougars?

"Obviously that is a competitive disadvantage going into that just like last week," Helton said Thursday morning. "I will say this, we are starting to garner players back. We got our first player back yesterday and we will receive more players back as the week progresses toward game week, but we are starting to gain players back and so that's a good sign that we're doing things the right way.

"Our medical team has led us in the right direction and hopefully that will garner enough to be a good football team on Sunday."

L.A. County guidelines, which USC must follow, require 10 days of isolation for those who test positive and 14 days of quarantine for those identified as at-risk through the contact tracing protocol. Helton did confirm that USC was able to start that quarantine clock for some of the players retroactively "back at basically the Utah game for a lot of these kids on that trip back home."

RELATED: Watch: Full video and transcript from Clay Helton's comments Thursday

USC initially reported that it learned of the first positive case Monday, Nov. 23, after that Utah game, then announced that Wednesday that a second player had tested positive and five others had been quarantined due to contact tracing. That Thursday, the Trojans then announced that a third player had shown symptoms and ultimately tested positive, two others players were subsequently identified as high-risk contacts and quarantined and then a fourth player tested positive last Friday, prompting the cancellation of the game vs. Colorado last weekend.

The game vs. Washington State was moved back from Friday to Sunday afternoon to allow for that unspecified number of players to pass protocols and be available.

USC returned to practice Tuesday after an extended layoff.

"The last couple days have been great to get back on the grass. Actually, kids look fresh. It actually felt like a bye week with them coming back, have some fresh legs, moved around extremely well. We got great news over the last three days. We have had five rounds of testing in the last three days and glad to say we've had all negative tests for our players and so we're really trending in the right direction," Helton said. "... We look like we're in a really good spot. And good Lord willing, cross your fingers, we will continue to be as we continue to work for Washington State. Our kids are looking forward to the opportunity."

The game vs. Colorado was cancelled because USC didn't have enough players at a certain position -- reported by Bay Area News Group's Jon Wilner and others to be the offensive line, where teams must have seven active players per Pac-12 rules.

As it remains unclear how many of the Trojans' starting offensive linemen will be on the field Sunday, Helton was asked about the challenge of potentially needing to turn to some younger players up front for the first time.

The Trojans have had only one offensive lineman miss any snaps this season -- that being center Brett Neilon, who was replaced for a game and a half by redshirt sophomore backup Justin Dedich.

The rest of USC's backup offensive line is young and untested, though, with true freshmen Casey Collier and Jonah Monheim at the tackles, and true freshman Courtland Ford and redshirt sophomore Liam Douglass at the guards.

Helton emphasized the opportunities those players had to rotate in with the first team during preseason camp as valuable experience should they be needed Sunday.

"This was a veteran football team and that offensive line was a veteran group. So the amount of reps that our 2s and 3s have gotten at all positions I think have helped us. ... So am I confident? Yeah, I'm confident in those guys," he said. "Anybody that walks in there. We put the investment in. I'm more excited, you know. We were gonna have to play some young players last week if the game went on and I was excited for them and they were excited. And I was to be honest with you disappointed and they were disappointed that they didn't get the opportunity because they prepared like starters and they've done it again this week. And if they're called upon, I know they'll do their job."

The CDC has shortened its guidelines for COVID-19 close-contact quarantine to 10 days if no symptoms appear and 7 days with a negative test.

But that won't have any bearing on USC's situation this week, as L.A. County is the ruling authority on the matter and has not changed its own guidelines in accordance yet.

"At some point in time it will come to us. Remember, that is issued by federal government then it has to go through state, then it has to go through local. So there is a time period. It will get to us at some point in time, hopefully sooner than later. But there's a filtering process that has to go," Helton said. "Believe me, I was as happy as anybody when I saw that, but they said, 'Coach, just realize there's a process to it and it does have to go through that process.' So just like we've done this whole time, we're going to listen to our federal, state and local guidelines, follow them to a T and when it gets to us, that'll be a happy day."

With the city of Los Angeles announcing tightened restrictions Wednesday night, Helton was also asked if he feared the Trojans might be put in a situation like Stanford has been in Santa Clara County, where it is not allowed to play or practice now. The Cardinal have spent this week in Seattle in advance of playing at Washington and will spend next week in Corvallis, Ore., before playing at Oregon State.

"Yeah, it's a been a lot of discussion here, just being honest with you. We always hope for the best but plan for the worst," Helton said. "The one thing I've learned about this situation and being a head coach is you have to be able to adapt and change directions, don't get frustrated with a situation -- they don't pay you to make excuses, they pay you to find answers. Thank goodness for our administration because we know things may change. We're hoping that our levels go down and we don't have to go to that shutdown, but if we do then we'll find the next answer.

"Stanford, I thought credit to David Shaw and Stanford University for what they did for their football team. ... Universities and teams are adapting and doing what they must to be able to play the game we love, so we're just taking it a day at a time, a test at a time, a practice at a time and make the most out of the day. The one thing I've learned about this whole situation is live in the moment, focus on the moment and when things change then be able to adapt and put your kids in the best place possible. If that comes down, I know [athletic director] Mike Bohn and [senior associate AD] Brandon Sosna are working on contingency plans to allow us to finish a great season."

Junior linebacker Palaie Gaoteote remains in the concussion protocol after taking a shot to the head in the Utah game.

"He is starting to feel better. I don't know if it will be this week to be honest with you, but he is starting to feel a lot better. Visited with him yesterday as well as our doctors," Helton said.

Fellow starting linebacker Ralen Goforth is making progress from a foot strain that sounds like it was more serious than initially conveyed.

"Ralen was actually moving around pretty well on the grass. That foot strain was a pretty significant one. It'll be close for Ralen, in my opinion. I think it'll be we will have to continue to monitor through the week, but he's actually working on the grass right now, EA is not," Helton said.

Junior Kana'i Mauga would start again in place of Gaoteote, and redshirt sophomore Raymond Scott would start in place of Goforth if he can't ... go forth this week.