Mora also announced that starting right guard Jeff Baca is expected to play Saturday after missing the last two games because of headaches.
Zumwalt, the Bruins' fifth-leading tackler, required "a lot of stitches" in his head and is unable to wear a football helmet because of the injury. He will not make the trip to Boulder for the game.
"He's got the week off, and we're hopeful and confident that he can be back next week," Mora said. "He was not being reckless. It was just an accident that happened just off campus."
Inside linebacker Damien Holmes will slide over and play outside in Zumwalt's absence, and Mora said he expects Ryan Hofmeister to get some playing time as a result. But Zumwalt, a junior, is one of the emotional leaders on defense, so that will be missed, Mora said.
"The thing you miss when Jordan is not out there is his energy," Mora said. "He just plays with maniacal effort all the time but somebody else has to do that and that's what we're trying to preach."
Mora said that he is "not a big fan of motorcycles and scooters," but that many UCLA students -- especially athletes -- ride them because of traffic and parking issues in and around Westwood. He looked into requesting that his players not ride them, but said he didn't know if he could institute such a policy.
"There are a lot of demands on these kids to be places on time and I don't know that I can do that," Mora said. "I think maybe a parent can do that or a school can put that in, but I don't know that it's the right thing for us to do."
Baca had a concussion during training camp and was thought to have had suffered another late in the game against Nebraska on Sept. 8. But tests revealed the headaches were not being caused by a concussion.
Baca practiced late last week and was probable to play against Oregon State, but was a game-day scratch after the UCLA medical team did not clear him. He sat out most of this week before returning to practice Thursday.