California found out Tuesday just how thin that line can be, missing key players at the three positions regarded as the strongest groups on the roster.
At linebacker, where the Golden Bears have plenty of candidates to replace stalwarts Mychal Kendricks and D.J. Holt on the inside, redshirt freshman Jason Gibson was effectively ruled out for the season after breaking several bones in his right foot Monday.
"He will be out probably three months," said head coach Jeff Tedford, who noted just 24 hours earlier there had not been any significant injuries so far in camp. "He's got two or three fractures, and then a separation in his foot, a Lisfranc injury there."
Team doctors must wait for the swelling to subside to see if Gibson will require surgery to repair the injuries.
Gibson, who played at Gardena (Calif.) Serra, had demonstrated tremendous athleticism during spring practice, earning frequent kudos from Tedford. However, he was unlikely to carve out more than a token role this season.
"He's one guy," Tedford said. "We've got a lot of linebackers. It's unfortunate because we were really looking forward to him competing."
Anderson is "pushing to be the No. 1 back," Tedford said, in part because of his adeptness as a pass blocker and receiver.
"Mentally, he's really sharp, doesn't make many mistakes," Tedford said. "All-around, he's an excellent football player. He's probably our most well-rounded back."
Sophomore Brendan Bigelow added several tough runs between the tackles, while redshirt freshman Daniel Lasco made a terrific sideline catch on a wheel route, adding to the wealth of talent available.
"Those top four backs are pretty special guys." Tedford said.
And on the defensive line, Cal spent the first part of practice with only five available players. Mustafa Jalil and Viliami Moala arrived an hour late because of summer school, while Deandre Coleman missed the session entirely.
But that created extra reps for redshirt freshman Todd Barr, who Tedford singled out as "really flashing a lot, making plays," albeit with a caveat.
"It'll be more like real football tomorrow," said Tedford, as Wednesday marks the first practice in full pads.
Quarterback Zach Maynard missed the first hour of practice because of summer school. Allan Bridgford received first and second-team reps in his place. … Freshman defensive back Jeffrey Coprich (broken jaw) will miss two weeks.
Dan Greenspan is the publisher of Cal Sports Digest and covers the Pac-12 for Fox Sports/Scout.com. Follow him on Twitter @DanGreenspan.