USC was severely shorthanded in last weekend’s 45-37 victory over Arizona.

Wideouts Jordan Addison and Mario Williams were unavailable — Addison was somewhat expected, Williams was a gametime surprise. Linebackers Eric Gentry and Ralen Goforth were out after suffering injuries in the Utah loss prior to the bye week. Left guard Andrew Vorhees missed the game, forcing the Trojans to shuffle up the line configuration. Rush end Korey Foreman missed the game. Running back Raleek Brown has only played a handful of offensive snaps in recent weeks.

Specifically on Addison, Gentry and Goforth, Riley said they’re hopeful this week.

“Good week for them,” Riley told reporters on Thursday. “Really good progress. We’ve been able to use them all here a little bit in the back half of the week, which has been promising. I think we’re going to be right up on the edge and have to make some tough decisions here right towards probably (Friday) afternoon and then into game time on where these guys are at. We’re pleased with the progress. That’s been important, obviously.

“None of these guys had simple, out-a-couple-of-days injuries. A lot of improvement. The bye week obviously helped. It was good to be able to get through last game without playing those guys and that time has certainly aided in it. We’ll have a bunch of close calls leading into Saturday.”

The Trojans are 7-1 on the year, 5-1 in Pac-12 play — meaning still right in the hunt for a spot in the Pac-12 title game — and sitting ninth in the initial College Football Playoff rankings.

They obviously need to keep winning, and if Riley feels like he needs to push things to beat Cal this weekend, we’ll see what happens. But USC also has a season-defining game looming. The Trojans host a Cal team this weekend that has lost four straight, then a Colorado team next week that has lost seven of its eight games.

On Nov. 19, the Trojans head over to Pasadena for a battle with the 12th-ranked UCLA Bruins. That one will influence both USC’s conference and national title hopes.

If Riley can buy a couple of weeks to make sure his stars are fully healthy for that tilt, trust he’ll do it. If he thinks pushing them now will risk missing them then, he isn’t likely to risk it.

Mason Murphy drew rave reviews from teammates and coaches alike after starting at right tackle. USC got 100-yard receiving performances from Kyle Ford and Tahj Washington. Riley appreciated that players stepped up, and said after the game the Arizona win was probably the proudest he’s been after any win this season.

A player to watch as USC closes out the year, specifically so if they have to continue getting creative in the passing game: Brown.

“Getting better. As I’ve said a couple times on here, it’s been good to have him back healthy the last several weeks,” Riley said of the freshman all-purpose back. “We’ve been able to play him a little bit, involve him on offense, involve him on special teams. He’s had some impactful plays for us, obviously. The great thing that’s happened is, past the plays on Saturdays, he’s been able to get a lot of reps in practice. And that’s what really hurt him, when he got injured. Obviously you want all these guys to get as many game reps as they can, but practice reps for a young guy that wasn’t here in spring ball, they’re so valuable. Because you just want to continue that development. You want to continue that knowledge.

“We think Raleek is heading in a great direction. He’s very, very talented. And our hope is if he continues to progress, that he can continue to have more of an impact here in the back half.”

USC and Cal (3-5, 1-4 Pac-12) kick off at 7:30 p.m. PT on ESPN Saturday evening.