PROVO — An intriguing subplot of Friday's BYU-Utah State showdown centers around a former Aggie who is now a Cougar.

BYU backup quarterback Riley Nelson caused an uproar around Cache Valley when he opted to transfer from USU while serving an LDS Church mission in 2008.

As a true freshman with the Aggies, Nelson started the final eight games of the 2006 season, completing 55 percent of his passes for 925 yards and six touchdowns while rushing for 290 yards.

"My time at Utah State is time that I cherish. I have a lot of fond memories and a lot of friends up there," Nelson said. "It was very important in my development. When the opportunity presented itself (to transfer to BYU), just for some personal reasons that I felt good about, I felt that I should make a change. I'm happy where I am. I'm glad to be here at BYU, glad to be a member of this team."

Starting quarterback Max Hall has enjoyed working with Nelson.

"Riley's a stud. I think he learned the offense very fast and he's been very good as a backup quarterback," he said. "We challenge each other to memorize scripts and plays and coverage recognition. We do a lot of things together. I think he's going to be a great quarterback here in the future."

As a Cougar, Nelson saw playing time in the fourth quarter against both Tulane and Florida State this season, completing 5-of-5 passes for 73 yards and a touchdown. He has also rushed for a TD.

"It would be awesome if we could get him in to play against Utah State," Hall said.

THE SERIES: When Bronco Mendenhall was named BYU's head coach five years ago, the Aggies hadn't played the Cougars since 2002 and they weren't on any of BYU's future schedules.

Mendenhall said at the time he would "love to add Utah State back to the schedule. I think the Beehive Boot (symbolic of in-state football supremacy) is a traditional thing. It's good for the state and it's good for both programs."

By 2006, the USU-BYU series was back, as the Aggies lost in Provo, 38-0. Last season, the Cougars beat USU in Logan, 34-14.

Besides Friday's meeting, BYU and Utah State are scheduled to play in 2010 (in Logan), 2011 (Provo) and 2012 (Provo).

Mendenhall reiterated his stance this week. "I like to play Utah State every year," he said. "I like the idea of there being a state champion every year between Utah, Utah State and ourselves."

FAMILIAR FACE: The Cougars know about Utah State's first-year offensive coordinator, Dave Baldwin. He spent the previous two seasons at New Mexico as the Lobos' offensive coordinator