On a corner blitz, Hogan ran into a blocker and fell to the ground, covering his face and then holding his right leg. He was taken away in a golf cart.
Mendenhall said the early report he got back from head athletic trainer Jeff Hurst was that Hogan suffered "maybe a quad strain, maybe a quad contusion."
Mendenhall said coaches are taking a lot of precautions in practices and scrimmages to protect the cornerbacks who haven't gone down.
"We have modified formats in about every way possible, with extending warmup time, with adding treatment time, with adding different movement patterns, with less hitting, with less being on the grass almost every day," he said.
Projected starting linebackers Kyle Van Noy and Spencer Hadley started taking live reps on Thursday and continued on Friday. Uani Unga is the probable starter at middle linebacker, while the starting buck linebacker position will go to either sophomore Manoa Pikula or oft-injured senior Tyler Beck.
"Great battle ... almost dead even," Mendenhall said.
Hadley could possibly play some buck linebacker as well because junior Alani Fua has played well in camp and deserves to see some time at outside linebacker.
Mendenhall said senior kicker Justin Sorensen "is separating himself" from the other kickers in camp, Trevor Samson and Moose Bingham, and getting close to locking up the starting job. Sorensen was 2 for 3 on field-goal attempts from 43 yards out, while Samson made his only FG attempt (33 yards) and Bingham didn't get one during media viewing time.
Defensive back Mike Hague (knee injury) was on the field Friday, having sat out most of camp. Mendenhall said Hague has a follow-up appointment with doctors on Monday and hopes he will be fully cleared to play. Hague can play all five positions in the secondary. ... The Cougars will scrimmage at LaVell Edwards Stadium on Saturday, but the event is closed to the media. It will be limited, with most first-stringers held out, and give coaches a chance to focus on younger players and backups and how they will be used this season. ... Freshman Parker Dawe has been moved from defense (nose tackle) to offense (center) and will now wear No. 54.