Bruins offense starts fast then stalls in scrimmage

Derrick Coleman rambled for 11 yards to the right. Coleman then bulled his way for six yards. From that point Saturday, UCLA’s “pistol” offense practiced gun control during the Bruins’ first scrimmage.

UCLA had only 23 yards in 13 carries. Richard Brehaut, who ran the first team with Kevin Prince (strained abdominal muscle), completed two of three passes for two yards, and had one pass intercepted.

Coach Rick Neuheisel said, “The drive started unbelievable. There were two unbelievable runs. That’s what we’re trying to get better at.”

Then …

“Absolute missed assignments, missed checks, missed things that cause the play to completely break up,” Neuheisel said. “We can’t play the play if one guy is going right and everyone else is going left.”

Things dissolved quickly. On the third play, Brehaut audibled into a play that doesn’t exist in the playbook, and Coleman lost five yards.

“We had a stretch [run] to the right and I saw Rahim [Moore] coming box, so I thought too many in the box to run that play,” Brehaut said. “I checked it to another play that we can’t even run in that formation.

“I have to get better in three weeks so if something is wrong with Kevin, I’m ready to come out here and perform.”

Neuheisel spread the blame around.

“What I asked the team at the end, when they look at themselves in the mirror, are they really putting everything into to be mentally sharp?” Neuheisel said. “ … When the lights went on and the coaches left, we lost our minds. We have to make sure the fog of war doesn’t get us.”

The Bruins scored one touchdown that came after receiver Rickey Marvray went high to make a 27-yard catch to the 10-yard line. Three plays later, UCLA scored … when the ball was snapped early, bounced through quarterback Nick Crissman’s legs to Johnathan Franklin, who used his speed to win a race to the flag.

Neuheisel was upbeat overall, leaning on the fact it was the first scrimmage.

“We didn’t have our starting quarterback,” Neuheisel said. “I think we’ll be fine. I think we’re where we need to be. … We’ll know three weeks from now.”

Life of Riley

Freshman strong safety Dietrich Riley was the standout of the scrimmage, as he intercepted two passes, one while playing with the first-team defense.

“I hope I was able to go out and show the coaches what I can do when they critique the film,” Riley said. “I know I can make plays. I got to eliminate the mistakes.”

Riley showed that he can make up for mistakes during the morning practice. He came across the field to lay a jarring hit on receiver Taylor Embree, knocking the ball loose.

“I turned my head fast enough and read the quarterback’s eyes,” Riley said. “I got to the middle fast enough to make that play.”

Prince update

Neuheisel said that Prince would likely return to practice Monday, though nothing is set in stone. Prince said he receives five treatments each day.

Asked when it would be concerning, Neuheisel said, “If we get all the way up to game week and he hasn’t played, then it would be a problem. But I think he’s fine.”

Quick kicks

Defensive lineman Wesley Flowers (strained back muscle) and safety Alex Mascarenas (hamstring) joined the injured list. … A constant presence at practice the last three days has been offensive lineman Darryl Jackson, who played at Lakewood Mayfair last year, committed to Southern Methodist, but was denied admission even though he was an NCAA qualifier.

chris.foster@latimes.com

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