Sarkisian reminded the Trojans that in exactly two weeks they would probably be in about the second quarter of their opener against Fresno State.
Then he said he told the players to ask themselves two questions:
"One, 'Am I ready to play in a game?' And two, 'If I'm not, what are those issues I need to get worked on and get fixed here over the next two weeks?'" Sarkisian recounted to reporters after addressing his team.
USC is still working to smooth out its new fast-paced offense and 3-4 defense.
The Trojans scrimmaged last Wednesday and will probably scrimmage again early in the coming week.
Quarterback Cody Kessler appears comfortable in the no-huddle format and will be supported by an experienced tailback corps, a suddenly deep group of receivers and an offensive line that could be a work in progress.
The defense is looking forward to the full return of defensive linemen Leonard Williams and Antwaun Woods, who have been nursing injuries.
"We're not ready, but that's why you have four weeks of training camp and not two," Sarkisian said. "But I think we're getting closer."
Williams returned to most drills Saturday, saying his shoulders felt good. Williams had offseason surgery on his right shoulder and suffered a left shoulder injury last week.
Williams sounded happy to be back in a leadership role.
"It's kind of hard for me to snap on guys and tell them to step up when I'm not practicing," he said. "I don't want them to look at me like, 'Dude, you're not even practicing. How are you going to snap on us?' Now that I'm back, it helps out a lot more."
Sophomore safety Su'a Cravens said the Trojans were close to ready.
"I don't think we're going to reach that full potential till halfway through the season, like most teams," he said. "If we were to play tomorrow, I think that we would do fine.
"But we need to do a lot better than we're doing."
In the aftermath of Jabari Ruffin's season-ending knee injury, Cravens also has been playing linebacker. He worked with the first-team defense at linebacker on Saturday.
"I'm cool with doing whatever the team needs me to do," Cravens said.
Cravens started 13 games, intercepted four passes and was a freshman All-American last season. Coaches told him last spring that he might assume a hybrid role.
"They told me it was an idea," he said, "and when Jabari got hurt it became reality."
The 6-foot-1 Cravens weighed 238 pounds before training camp but is now at 219.
Sarkisian said Cravens could play linebacker against spread teams such as Arizona State, Arizona and California.
"He can play man-to-man on receivers, he can blitz off the edge and he can still fit in the run game," Sarkisian said.
When the Trojans play teams such as Stanford and Oregon State, which run more traditional offenses, Cravens would play more safety.
Cravens' versatility and high football IQ, Sarkisian said, "allows us the luxury of moving him around."
Freshman Adoree' Jackson, who has been sidelined for nearly a week because of a foot injury, returned to full participation in team drills. He played cornerback and returned kicks.
Jackson was "a little but rusty," Sarkisian said, but he continued to show playmaking ability.
"It's exactly what we saw early on, but technique-wise, when you don't practice for that long, you can be a little rusty," Sarkisian said.
Tailback Justin Davis, offensive lineman Damien Mama and linebacker J.R. Tavai suffered ankle injuries. Sarkisian said first reports were that the injuries were not serious. Tailback Anthony Brown remains sidelined because of a hyperextended elbow.