How a converted quarterback became USC’s most crucial question mark entering the season

Deontay Burnett practiced over-the-shoulder catches with a fellow receiver after USC’s practice Tuesday. Burnett would run in place, look up for the ball, catch, then lob one back. The throws to Burnett came in cleaner than the ones he threw out. They spun in a tighter spiral. They hit Burnett just where he was expecting.

His partner was Jalen Greene, after all. Greene had been a quarterback once. Now he might be USC’s most important question heading into the season as a receiver.

The Trojans’ offense will depend on how well the converted quarterback develops into a legitimate threat on the perimeter. As USC cycled in receivers during training camp, Burnett and Greene were the mainstays. They ran with the first team from start to finish.

Burnett was not a surprise. Greene’s emergence was less likely. For a while, his greatest appeal was as a utility man.

Greene signed with USC as a quarterback. He played there his first year, when he redshirted, but his accuracy was dicey, and he saw scant opportunity for playing time with Cody Kessler returning and Max Browne ahead on the depth chart. He asked then-coach Steve Sarkisian if he could switch to receiver.

His body rebelled. He tore both of his hamstrings, twice, he said, early in the transition. He’d been mobile as a quarterback. But he wasn’t used to running, planting and stopping so violently.

By last season, as a sophomore, he’d gained confidence, but the depth chart at receiver was clogged, too.

He played some — about 10 non-special teams plays per game. He still sat in on some quarterback meetings. Then, when Browne transferred before the Rose Bowl, USC shuffled him back to quarterback. He divided his time between the two positions. If Sam Darnold got injured, USC needed him to be ready.

Now USC needs the utility man to occupy the position formerly held by stars like JuJu Smith-Schuster. Can he produce close to the same level?

As Greene threw with Burnett on Tuesday, offensive coordinator Tee Martin stood nearby and declared Greene the team’s most improved receiver.

USC wide receiver Jalen Greene, shown dodging a Notre Dame defender on Nov. 26, spent his first season and a half at USC as a reserve quarterback behind Cody Kessler and Max Browne.

(Luis Sinco / Los Angeles Times)

“He’s really impressive,” Martin said. “I’m excited about where he’s at.”

Greene’s production last season didn’t portend a breakout: eight catches for 116 yards. He also rushed four times for 12 yards.

But Greene’s versatility also makes him an untraditional receiver, whose value could be different than receivers in USC’s recent past. Martin plans to add a package for Greene each week to “allow him to do what he can do and show his talents to throw the ball, to run with the ball and do different things, and be creative that way.”

Coach Clay Helton said Greene would be a receiver primarily. But Helton said he wants “to be able to use him in different quarterback situations, almost like a wildcat quarterback. You’ve seen him involved with trick plays. He’s just so dynamic.”

Greene said he did not begrudge USC for the way he has switched positions. The former Gardena Serra standout knew his role, he said, and he was happy with it.

He’d initially wanted to be a quarterback, he said, “to represent for my family and my community. I’m a kid born and raised in LA.”

In other words, “Not too many black quarterbacks played here,” Greene said.

USC has had several black quarterbacks but none recently. The Pac-12 Conference’s first black quarterback, Willie Wood, played at USC (when the conference was the Pac-8). USC’s Jimmy Jones was the first black quarterback to appear on the cover of Sports Illustrated. Rodney Peete was an All-American quarterback. But USC’s last starting black quarterback was Reggie Perry, in the early 1990s.

“That was definitely something that would’ve been big, and — how can I say it — just been something really exciting, really left a mark,” Greene said.

Greene said once he switched, he had no regrets.

“Even if I were to move to safety, I feel like if that’s the position I play, I’m going to go in 1,000%,” Greene said.

Greene worked to build a rapport with Darnold in the offseason. He drove to San Clemente, where Darnold lives, to work out.

Darnold said Greene often already knew where Darnold wanted him to be.

“He kind of has that quarterback mind, I guess you could say,” Darnold said. “In terms of, sometimes you just need to get open, and he’s aware of that.”

Greene said he is “well away” from replacing last year’s departures, Smith and Darreus Rogers.

But, he said, “My thing is just trying to get respect as a receiver, just showing that I can go out and, like you said, not just replace but actually be better than what they were.”

Shotgun Spratling contributed to this report.

zach.helfand@latimes.com

Follow Zach Helfand on Twitter @zhelfand