Juniors Brandon Hance and Matt Cassel and sophomores Matt Leinart and Billy Hart divided snaps during an intrasquad scrimmage Friday at Howard Jones Field. The Trojans will take a week off before resuming practice March 25.
"They all played pretty well," offensive coordinator Norm Chow said of the quarterbacks. "I don't know [who's No. 1]."
Chow said he would like to establish a front-runner before the end of spring practice, which lasts two more weeks.
"We can't keep doing this," he said. "Hopefully we'll have some answers soon."
Coach Pete Carroll said Hance, a transfer from Purdue, and Hart have gotten more reps in the spring because they needed time to learn the offense. Cassel and Leinart were Palmer's primary backups last season, though neither played much.
"We'll assess it at maybe the end of the third week of [spring] practice," Carroll said.
"Right now there's no need to do anything about it."
Carroll said he's encouraged by the competition at middle linebacker and strong safety, where the Trojans must replace starters Mike Pollard and Troy Polamalu.
Sophomore Lofa Tatupu, son of former USC fullback Mosi Tatupu, and junior Daniel Urquhart are splitting time at middle linebacker. Sophomore Mike Ross, who has adopted Polamalu's No. 43, and freshman Darnell Bing are competing at strong safety.
Junior Jason Leach, who backed up Polamalu last season, has moved to free safety, taking over for DeShaun Hill.