Rosen saw constant pressure while playing with second-string offensive linemen for the majority of his time on the field.
Selected with the 10th overall pick in the 2018 NFL Draft, Rosen escaped the pocket and had a 21-yard completion over the middle to tight end Gabe Holmes. He completed 6-of-13 passes for 41 yards without a touchdown or interception, although he would have had one of the latter had Chargers cornerback Desmond King held onto one errant toss.
"I thought I did some good things, some bad things, but for the most part, it was a step in the right direction," Rosen said. "The almost pick six goes into the 'bad' category."
Rosen also was troubled with several poor snaps from center Daniel Munyer, a fact noted by Cardinals head coach Steve Wilks.
"It always throws you off a little bit, because you're trying to keep your eyes down the field and see the defense, but he has to make sure he can secure the football," Wilks said. "We've got to do a much better job there, whoever is at the center position, of getting the ball back to him."
Rosen passed for 3,754 yards and 26 touchdowns with 10 interceptions in 2017 with UCLA. He posted career numbers of 9,301 yards passing with 59 touchdowns and 26 interceptions in 30 games.