Manfro was taken off the practice field on a cart after injuring his knee Tuesday. The junior was part of the No. 11 Bruins' three-man rotation at the position with Paul Perkins and Jordon James, and he often was featured as a receiver out of the backfield. UCLA spokesman Steve Rourke confirmed Manfro's injury Wednesday.
Manfro caught 37 passes for 400 yards and two touchdowns over the past two seasons and was featured on special teams.
Offensive coordinator Noel Mazzone said Manfro is "an awesome young man that was very valuable to this football team, but there will be somebody that steps up."
When the Bruins host Memphis at the Rose Bowl on Saturday, freshman Nate Starks is likely to take Manfro's spot in the offense, offering more size than Perkins and James at 5-foot-11 and 205 pounds.
"It will be fun to watch him play Saturday night. It will be fun to hand him the ball," Mazzone said before adding, "Note to self: Hand him the ball."
UCLA's ground game struggled in a 28-20 win at Virginia last week. Perkins rushed for 80 yards on 16 carries, leading an offense that totaled 116 yards rushing and averaged just 3.0 yards per carry.
"It wasn't good," Mazzone said. "It was hit and miss, no rhythm to it. We've always been able to run the football. It hasn't been an area of concern for us, so we're not going to panic. We got to be a little bit better, and I got to do a better job."
Getting starting center Jake Brendel back from a knee injury soon should help address issues on the offensive line, which allowed five sacks against the Cavaliers. Defensive lineman Eddie Vanderdoes said that group has been "a lot more physical this week."
That should help the UCLA offense catch up to its defensive counterparts in touchdown production.
Quarterback Brett Hundley's touchdown run accounted for the only points on that side of the ball versus Virginia, compared to two interceptions and one fumble return for touchdowns.
Mazzone couldn't remember that happening previously to an offense he coached. He joked that the defense should enjoy it while it lasts.
"I told them I spotted them two, but it's not going to happen anymore," Mazzone said.