Bruins receiver Demetric Felton surprisingly successful at running the ball, but there’s one small problem

UCLA’s most efficient running back against Hawaii was a receiver.

Demetric Felton, a speck of a player at 5 feet 10 and 185 pounds, carried the ball three times for 37 yards and a touchdown during the Bruins’ 56-23 victory over the Rainbow Warriors on Saturday at the Rose Bowl, including a 25-yard gain on a fly sweep.

His average of 12.3 yards per carry helped boost the team’s otherwise modest rushing total.

However, Felton won’t become a regular part of the running back rotation because of durability concerns related to the redshirt freshman’s size.

“If you tried to run him a lot, it wouldn’t be the best thing for your football team or for him,” UCLA coach Jim Mora said. “That doesn’t mean he won’t get some shots there in some special situations like he did on Saturday, but he won’t be an every-down back.”

UCLA gained 132 rushing yards against Hawaii, which qualified as significant progress given that the Bruins rushed for 63 yards in their opener against Texas A&M. But UCLA is averaging only 3.8 yards per carry through its first two games and ranks 108th out of 129 major college teams with 97.5 rushing yards per game.

One positive development Saturday was some mammoth holes created by the offensive line. Starting tailback Nate Starks dashed through one for a 25-yard gain in the first quarter.

“In terms of our run efficiency, it was really good,” Mora said. “There were some really nice holes, so that was encouraging.”

Starks finished with 42 yards in seven carries and Bolu Olorunfunmi had 32 yards in six carries. A UCLA tailback has not rushed for 100 yards since Paul Perkins ran for 121 versus Washington State on Nov. 14, 2015.

Two thumbs up

Quarterback Josh Rosen’s latest superb performance didn’t look any different when Mora reviewed the game footage.

“He was still 22 of 25 and he looked really good,” Mora said. “He looks more and more comfortable playing in this offense, more and more comfortable with the receivers that he’s throwing to and just understanding how to process information and apply it going forward.”

It’s hard to imagine Rosen’s numbers getting much better. His nine touchdown passes are tied for first in the nation, his 410 passing yards per game rank third and his 185.2 passing efficiency ranks 12th.

Quick hits

Rain associated with Tropical Storm Irma is expected to end in Memphis by midday Wednesday, according to weather.com. The forecast for Saturday’s game is sunny with a high of 88 degrees. … UCLA was ranked No. 25 in the Associated Press poll, the Bruins’ first appearance in the rankings since starting 2016 at No. 16. … UCLA’s game at Stanford on Sept. 23 will start at 7:30 p.m. and be televised by ESPN.

ben.bolch@latimes.com

Follow Ben Bolch on Twitter @latbbolch