This year, the left guard spot on Arizona’s offensive line has been like a revolving door and that’s going to continue Saturday at Oregon State.

No. 1 guard Chris Putton hurt his ankle in the first half against No. 9 Oregon, and hasn’t yet returned to practice. Backup guard Shane Zink sprained his foot at USC — an injury that head coach Mike Stoops said could keep him out for the rest of the season.

Now it’s up to redshirt freshman Carter Lees, who replaced Zink when he went down in the second half.

“God, I’ve got to stay healthy,” said Lees, who missed the last two weeks of fall camp because of a bulging disk in his neck. “I’ve been battling my way back into the lineup, so I’ve been preparing.”

Lees helped jumpstart Arizona’s best offensive performance of the year, totaling 554 yards at USC, 129 of which came on the ground — easily Arizona’s highest total of the season.

The addition of Lees to the lineup meant that Arizona had three freshmen on its offensive line.

But quarterback Nick Foles said that he doesn’t mind the number of different starters that Arizona’s had on the line, as long as they keep protecting him.

“I know they’re young, but I think they’re doing a good job and they did a great job last week,” Foles said. “I’m sticking with them, and they’re sticking with me and supporting with me.”

But Lees, a Sugar Land, Texas native, said that he wasn’t prepared for the possibility of getting into Saturday’s game.

“It was my first time going to an away game,” Lees said. “I went blank. They were like ‘Carter, get in.’ then I was like ‘Oh, that’s me.’ Then instincts just took over.”

Lees said that he had some hesitation on his first snap or two because it was his first time on the field in college, and was against a storied program like USC and in a historic stadium like the Los Angeles Memorial Coliseum.

But after the first few snaps, he was reminded why he’s playing at a major Division I program.

“I just came out and smashed into someone, and I was like, ‘Hey, I can hang with these guys,’” Lees said. “There’s always that hesitation, but now my confidence is through the roof.”

And Foles wants the O-line playing with as much confidence as possible.

“I have a lot of confidence in them,” Foles said. “It doesn’t make a difference who’s in there. They’re gonna play hard, and they’ve been doing.”