Column: UCLA and Josh Rosen make the grade, but tougher tests loom

The preliminaries ended on a hot Saturday evening, when UCLA wore down Nevada Las Vegas in a tedious game that was unnecessarily close until early in the third quarter. By the time freshman quarterback Josh Rosen emerged from the locker room after the Bruins’ 37-3 victory at Sam Boyd Stadium, Saturday night had become Sunday morning and it was probably past his usual bedtime.

“We’ve got a lot to learn when we watch the film tomorrow,” Rosen said, then paused. “Or I guess you could say later today.”

Their labor moved the No. 10 Bruins a day closer to the meat of their schedule and a step up in the quality of their competition. Although linebacker Myles Jack insisted “all cylinders are firing now,” some of those cylinders will need tuning. Next up is BYU, 2-0 after its rally Saturday against Boise State, followed by a trip to Arizona to open Pacific-12 play.

“We definitely understand what’s ahead of us. The growth with our team, with what fans and we wanted to see, was how we handled these first two games,” Jack said. “Moving into BYU and conference play, if we did what we were supposed to do in these games, we would feel pretty good moving forward.”

They have reason to feel good, and Coach Jim Mora found still more when he reviewed game film Sunday.

Their defense was solid again in holding UNLV to a fourth-quarter field goal, but Mora acknowledged it was difficult to get a complete measure because the Rebels lost their quarterback to injury in the first half. Mora found unqualified positives in kicker Ka’imi Fairbairn (three for three on field goals) and the defensive line’s strength after losing junior Eddie Vanderdoes to a knee injury last week.

“We actually played better offensively than maybe it felt after the game,” Mora said Sunday. “Josh did a really nice job of handling all the pressure variations that they brought, because they brought a million of them, and once again showed great pocket awareness, pocket presence.

“The offensive line was very solid again. No sacks. Averaged 5.8 [yards] a carry again. Those guys are doing a nice job for us.”

Rosen’s continuing education included his first interception. He was 22 for 42 for 223 yards and one touchdown and wasn’t as precise as in his debut against Virginia, when he was 28 for 35 for 351 yards and threw for three touchdowns. Mora said Rosen missed some throws Saturday “just a little bit,” but was pleased Rosen remained calm when things didn’t go as planned. “I told you to temper expectations. It ain’t going to be as pretty every week as it was last week,” Mora said. “So it’s just a great learning experience for him and for us.”

Rosen gracefully took responsibility. “I’ve definitely got to step up my game. A lot of it was on me,” he said. “I’m not too proud of how I played but I definitely think we’ll get better as a team and move forward.”

Ideally, that’s the best outcome of these early games — that Rosen learns how to handle defenses he hasn’t seen before and at a tempo he never had to sustain before. A little adversity could be a good thing. “I thought it was great for Josh, it’s a great experience,” offensive coordinator Noel Mazzone said. “At one point he’s going to see stuff like this. And so this is the first time really. He didn’t see it really last week.

“I think he came out in the second half and settled down a little bit and had his feet underneath him a little more and stopped thinking every throw has to be a touchdown pass.”

Receiver Jordan Payton, who made five catches for 70 yards and one touchdown Saturday, defended Rosen. “Overall we got a win, for a freshman quarterback to come on his first away game and throw for 240 yards … for him to get this win and put up 37 points is fantastic,” Payton said. “I can’t sit here and be complaining about that.”

And he shouldn’t. But Rosen and the Bruins will have to adjust fast as the schedule becomes more challenging.

In viewing film of the UNLV game Sunday, Mora saw areas that will need polishing.

“We’ve been good in the red zone in terms of scoring points but I’d like to see us improve our touchdown efficiency in the red zone,” he said. “Defensively, sacks, we’ve had good pressure on the quarterback but we’ve had only one recorded sack in two games so we need to improve that aspect. And on special teams I’d like to see us be more efficient in the punt-return game with regards to getting blockers away from poor kicks and getting good blocks and setting up some good returns.”

No question, the preliminaries are over and the Bruins’ real test is about to begin.

helene.elliott@latimes.com

Twitter: @helenenothelen