QB Josh Rosen debuts when No. 13 UCLA hosts Virginia

PASADENA, Calif. (AP) Welcome to the Rosen Bowl, Virginia.

UCLA freshman quarterback Josh Rosen's debut is the main event Saturday in the season opener for the 13th-ranked Bruins and the Cavaliers.

The 18-year-old prodigy will replace three-year starter Brett Hundley on Pasadena's famous turf against a solid ACC opponent. The Bruins are quietly thrilled by Rosen's maturity and aptitude in practice, but it's finally time to see how quickly it will translate into games.

''This kid is truly special, so it's going to be great to see him grow up,'' UCLA receiver Jordan Payton said.

Opposite Rosen will be a Virginia defense with an accomplished secondary and a burning desire to start off the season with a landmark victory. Rosen's strong arm and uncommon poise easily won him the starting job in fall camp, but he realizes Saturday is a whole different kind of test.

''A lot of times with freshmen, they get on the field and their mind is just wandering,'' UCLA linebacker Deon Hollins said. ''Big lights, big crowd, college football. (Rosen) is just so focused all the time, and that is what separated him from other freshmen. He is tremendously smart and talented.''

While UCLA's first three seasons under coach Jim Mora have been the winningest stretch in school history, Virginia coach Mike London is on an undeniably hot seat after going 23-37 in his first five seasons. With a perilous September schedule that includes home games against Notre Dame and Boise State, the Cavaliers can't afford to start slowly.

Virginia has watched tape of Rosen in high school, but otherwise will rely on its knowledge of UCLA offensive coordinator Noel Mazzone's schemes for its preparation.

''We'll get in the game and start playing against him to actually find out what his strengths are, and try to find his deficiencies as well,'' London said.

Other things to watch when the Cavaliers step on the Rose Bowl turf for the first time:

DO IT AGAIN: The game is a rematch of last season's opener, won 28-20 by UCLA in Charlottesville on the strength of three defensive touchdowns by the Bruins in the second quarter. Ishmael Adams returned an interception for the first score, but the all-conference cornerback is missing the rematch after his arrest on suspicion of felony robbery last weekend.

JOHNS RETURNS: A silver lining from last season's loss to UCLA was the play of Virginia quarterback Matt Johns, who came on late in the second quarter and eventually passed for 154 yards and two scores, nearly leading a comeback. Johns threw his first career passes against the Bruins, and the junior is back as the Cavaliers' starter this season.

GET HIM: The logical tool for disrupting a freshman quarterback is aggressive pressure, and Virginia doesn't hide the fact that it will get after Rosen: ''It would be safe to assume that,'' London said dryly. UCLA's veteran-laden offensive line will attempt to keep him safe, and it has experience with Virginia's inventive defensive front. ''They almost always slant,'' center Jake Brendel said. ''They almost always bring one guy, so we're expecting to ... pick up all their different pressures and all the different things they can bring.''

SUPPORT GROUP: Rosen is new, but he isn't alone. Along with his veteran offensive line, the freshman has the support of the Pac-12's top rusher, Paul Perkins, and a solid group of receivers. Rosen's teammates are confident they can minimize the stress on their new passer with a comprehensive team effort.

LONG TRIP: Virginia hasn't won a game west of the Mississippi River since Sept. 25, 1999, and is just 4-13 in school history. The Cavaliers are facing a Pac-12 member for the sixth time after going 0-5 previously.