UCLA Coach Jim Mora isn’t counting out a return by quarterback Josh Rosen this season

The wait for Josh Rosen continues, though it may not extend into 2017.

UCLA Coach Jim Mora on Tuesday said he had not counted his sophomore quarterback out from a return this season, even though Rosen has been sidelined for more than three weeks because of an injury to his throwing shoulder.

“Josh is a tough son of a gun,” Mora said during a conference call with reporters on the eve of the Bruins’ traveling to Boulder, Colo., for a Thursday evening game against No. 21 Colorado at Folsom Field. “All you have to do is go back and look at the Arizona State game when he fought his way back onto the field and did everything he could to lead us to victory. So I put nothing past Josh with regards to what his future this year looks like.”

Rosen’s return did not appear imminent Saturday during the warmup portion of practice, when it looked like he intentionally short-armed a few passes as a protective measure. He did not attend the portion of practice reporters were allowed to observe Sunday or Monday.

In Rosen’s absence, UCLA’s record has fallen to 3-5 overall, 1-4 in Pac-12 Conference play. Mike Fafaul is expected to start against Colorado, which is 6-2 overall, 4-1 in conference games.

Mora mentioned a nerve issue in Rosen’s shoulder last week but backtracked Tuesday, saying “there is no nerve damage to his shoulder.”

“I’m not a doctor, so when I’m asked a medical question I do the best I can to answer it,” Mora said. “But I didn’t go to medical school, believe it or not. … So when I do give an answer regarding an injury, I’m not sure that it’s always going to be the correct verbiage.”

Richard Ferkel, an orthopedic surgeon at the Southern California Orthopedic Institute who has not examined Rosen but has worked with professional, college and high school football players dealing with nerve issues, said they tend to heal very slowly.

“It’s pretty rare,” Ferkel said, “but when it occurs, particularly in the throwing shoulder, you can’t really do much because the nerves control the function of the muscles of the shoulder, particularly the rotator cuff and deltoid muscles.”

Ferkel said nerve tests performed four to six weeks after an injury can help pinpoint the nature and extent of any damage and whether multiple nerves are involved. A followup test a month later can determine the progress of the nerve healing.

Certain vitamins can help the healing, Ferkel said, but rest is the primary prescription for athletes recovering from nerve issues.

Rosen has been relegated to a supporting role in recent weeks, mentoring Fafaul. The fifth-year senior produced a record-setting performance against Utah on Oct. 22 but has not led the Bruins to victory in either of his starts.

Never give up

“Fight on” is taken. How about “Bear on”? “Claw on”?

All of those mantras would fit UCLA’s combative spirit amid circumstances that might make others surrender.

Not even 4 1/2 minutes into their most recent game against Utah, the Bruins were down by 14 points while playing with a backup quarterback and coming off back-to-back losses that had already sunk their Pac-12 title hopes.

It was easy to imagine what might happen next.

“I’ve been around teams that when it’s not going well, when they’ve lost a couple of games, you get down 14-0, the tent just collapses,” Mora said. “We don’t do that.”

Just the opposite. The Bruins seemed invigorated the rest of the first quarter, scoring three unanswered touchdowns to take the lead and continuing their season-long trend of battling to the end of every game. They rallied twice more against the Utes to either tie the score or take the lead during an eventual 52-45 loss that had a familiar feel to it.

“We’ve got fighters, we’ve got savages on this team,” defensive end Takkarist McKinley said. “We’ve just got to find a way to get ‘W’s.’ ”

UCLA needs to win three of its final four games to go to a bowl, and a good starting point for the turnaround would be Thursday against the Buffaloes. Several players have talked in recent days about going “1-0,” as if this week’s game is all that matters.

“The goal is we’re trying to get to six wins, trying to get that bowl game,” tight end Austin Roberts said. “With four games left, to get that four-game win streak, we gotta go 1-0.”

ben.bolch@latimes.com

Twitter: @latbbolch