Freshman Iman Marshall is taking advantage of opportunities.
Senior Kevon Seymour and sophomore Adoree' Jackson are USC's returning starting cornerbacks, but Marshall appears on track for a significant role this season.
"He came here pretty well-equipped," defensive backs coach Keith Heyward said after practice Saturday.
At 6 feet 2 and 200 pounds, Marshall's size is reminiscent of former USC All-American safety Darnell Bing, another Long Beach Poly product.
But Marshall is playing cornerback.
"Great player, physical guy," Jackson said. "He's just out there wanting to learn. He wants to get better."
When asked before camp began if Marshall would play cornerback or safety, Coach Steve Sarkisian said he was eager to see how Marshall would match up against JuJu Smith-Schuster and other elite USC receivers.
Marshall has not backed down.
"He's a physical guy, so he can get up there and handle the physicality of guys like JuJu and Darreus [Rogers]," Heyward said. "He can run well too. He just needs to get better at finishing."
Marshall is still working to consistently grasp alignments and technique, according to Heyward.
"I'm happy about his play thus far," he said. "But we've still got a long way to go."
Marshall could get increased opportunities Sunday depending on the condition of Seymour, who did not finish practice after suffering a left knee injury.
Sarkisian was not scheduled to address reporters Saturday. Through a school spokesman, he said Seymour's injury was not serious.
After a productive 2013 season as a reserve linebacker and special-teams player, Jabari Ruffin anticipated playing a key role in 2014.
A knee injury suffered after intercepting a pass during training camp last summer ended those hopes.
"It was one of the worst things I've ever had to deal with," Ruffin said.
The 6-3, 245-pound Ruffin said he valued the experience gained from working his way back after surgery.
Now the fourth-year junior is one of nine players competing for playing time at outside linebacker. Coaches are limiting his snaps, but he is making the most of them.
"I feel like I'm making up for lost time," said Ruffin, who came to USC from Downey High. "I just want to be a good pass-rusher and be a guy that can set the tempo, whether that means a big hit or a rush off the edge."
Temperatures were in the 90s during practice, which taxed some players but apparently didn't bother others.
Jackson, who grew up in Illinois, said he and teammates such as safety Leon McQuay III, a Florida native, were accustomed to practicing in 100-plus-degree temperatures, with humidity.
"So this is a good day for us," Jackson said.
Players were rewarded with flavored-ice treats after the workout from a truck that drove onto the practice field.