During the Trojans' first three training-camp practices, Jackson played cornerback, wide receiver and also returned kicks.
On Thursday at the Coliseum, the freshman's workload increased when he took a handoff out of the backfield and showed his ball-carrying ability.
"I'm trying to find a flaw right now with the guy," Sarkisian said, "But he's prepared, he studies, he gets his rest, he recovers, he comes energized and, ultimately, he knows what he's doing and he's making plays.
"So, we'll see how far he can go with it."
USC has not made first-year players available to the media.
But the 5-foot-11, 185-pound Jackson is making a statement with his play.
"So much of what we're doing is trying to gather information," Sarkisian said. "He's such a different athlete, such a unique player. Where is he best suited for our team right now?
"That might not necessarily be the same thing three years from now, but where can he help the most right now?"
Before training camp, Sarkisian said that freshmen JuJu Smith and Rahshead Johnson might also get looks on offense and on defense.
Both have played only receiver.
Their status as possible two-way players will be evaluated by the coaching staff Saturday, Sarkisian said. The Trojans will not practice, but coaches will meet to discuss the entire roster after a week of workouts.
Meantime, Sarkisian is monitoring Jackson's workload.
"We've done everything in moderation, really counted his reps, so we know exactly what he's doing in every phase," Sarkisian said. "If you look at sheer number of reps, his reps aren't more, necessarily, than other guys but it is a lot mentally."
Safety Su'a Cravens practiced after sitting out most of the last two days because of strep throat.
"I don't really like missing practices," he said. "Everybody might think it's great to get a couple days off from camp, but you're behind."
Cravens was a Freshman All-American in 2013 when he started 13 games and intercepted four passes.
But he said he considered himself "third-string" after Thursday's workout.
"I was slow on my assignments, I was thinking too much, I let a couple guys beat me," he said. "I let Adoree' beat me. You should never let a freshman beat you across the middle, especially when I knew what he was doing."
By the Aug. 30 season opener against Fresno State, Cravens expects to be fully recovered and playing at full speed. He will be one of the leaders of a Trojans defense that is regarded as a strength of the team.
"By the end of camp," he said, "I will definitely be that guy you guys all know."
Haden reacts to NCAA vote
USC Athletic Director Pat Haden described it as "an expected result."
That was Haden's reaction to a vote Thursday by the NCAA board of directors that grants the "Power Five" conferences more freedom to pass legislation without approval of the full NCAA membership.
"It doesn't mean those outside the Power Five can't do more, but we have resources that will probably let us do more than some other conferences," Haden said, adding that the vote was "a good thing for student-athletes and certainly a good thing for USC student-athletes."
Haden said, "I've been discussing that we need to be doing more for these kids for years, and this is just the first step I think."
Pac-12 Conference athletic directors are scheduled to meet this month in San Francisco.
"We'll be talking about this a lot," Haden said.
USC announced "a number of significant upgrades" and features designed to enhance the fan experience during Trojans games at the Coliseum.
New food offerings, mobile ticketing, parking improvements and pregame clubs in the tailgating area are among the new features. USC previously announced that there would be 10 on-field suites behind the end zone at the peristyle end of the stadium.
Food items available at concession stands inside the stadium will include "smoked ribs, sliced steak sandwiches, artisan sausage, signature pizza, fried chicken and funnel cakes, as well as vegetarian and gluten-free items."
The school also said there have been improvements in wireless coverage and restrooms.
USC will practice in full pads for the first time Friday… During Thursday's workout, which was conducted in helmets, shoulder pads, shorts and cleats, Sarkisian stopped practice and had players run sprints because too many were "going to the ground" as a result of unnecessary hits. "It was time to send a little bit of a message to get their attention and I thought they responded very well," Sarkisian said, adding, "I'm not worried about the guy making the tackle or the guy getting tackled. I'm worried about the other 20 players on the field that can get rolled up on."
Follow Gary Klein on Twitter @latimesklein