Penn State quarterback Ta'Quan Roberson (2) looks to pass during the second half against Iowa last weekend.

STATE COLLEGE — Since quarterback Sean Clifford arrived on campus, Penn State has never been without his services for an extended period.

Now, with their third-year starter nursing an unspecified upper-body injury, the No. 7 Nittany Lions might have to find a way to win without him. First, they need to figure out how to get the offense working again with backup Ta’Quan Roberson at the helm.

After Clifford was knocked out of Penn State’s loss at No. 2 Iowa on Saturday, Roberson entered and the offense struggled mightily. The Nittany Lions had just 95 yards in the second half, and Roberson completed only 7 of 21 passes for 34 yards with two interceptions.

“We use the same system with Sean as we did with Ta’Quan and it didn’t work,” Penn State coach James Franklin said. “And obviously, it became a significant issue in the game.”

The Nittany Lions are hoping Clifford’s absence, however long it may be, won’t torpedo their College Football Playoff hopes. They get a break this week and will focus on getting Roberson more work with the first team before hosting Illinois on Oct. 23.

Penn State still has a path to the playoffs by way of winning the Big Ten East and the conference championship game. Whoever the quarterback is, he’ll have a tough slate.

The Nittany Lions visit No. 6 Ohio State on Oct. 30, host No. 8 Michigan on Nov. 13 and close the regular season with a trip to No. 10 Michigan State on Nov. 27.

“I know my teammates got my back,” Roberson said. “I got their back, so I’m just focused on next week.”

Previously, Roberson was focused on the long game, learning the ropes behind the scenes to succeed Clifford eventually under normal conditions. By all accounts, Roberson’s development was going well.

The redshirt sophomore threw for 4,898 yards and 59 touchdowns over his final two seasons at DePaul Catholic High in New Jersey and had raised eyebrows in Penn State’s training camp with his arm strength.

“The ball can really pop out of his hand, man,” offensive coordinator Mike Yurcich said. “He’s got really good explosion. He’s got a really good whip with his arm, and yet he’s got really good core strength that allows him to rotate and really snap the ball out there.”

Roberson played cleanup duty in Penn State’s wins at home against Ball State and Villanova, but his first experience against a contender came in a much tougher spot.