Jeffrey D. Allred, Deseret News
Brigham Young Cougars quarterback Taysom Hill (4) celebrates his touchdown against Hawaii with Brigham Young Cougars quarterback Riley Nelson (13) in Provo Friday, Sept. 28, 2012.

PROVO — As BYU prepares for its big in-state showdown against Utah State, there are questions about which quarterback will start for the Cougars.

It could be senior starter Riley Nelson, who is nursing an injured back and was sidelined last week, or it could be true freshman Taysom Hill, who led the offense to a 47-point, 540-yard outburst in last Friday's 47-0 victory over Hawaii.

Asked after the game which quarterback will start Friday (8:15 p.m., MT, ESPN) against the Aggies, coach Bronco Mendenhall replied, "Riley Nelson, hopefully. If he is capable and ready to play, then he'll be our starter."

But will Nelson, who grew up an Aggie fan and played his freshman year at Utah State, be healthy enough to play Friday?

Meanwhile, Utah State has no questions at quarterback. Chuckie Keeton is coming off a career-best performance in last Saturday's 35-13 victory over UNLV, completing 20-of-33 passes for 402 yards and four touchdowns.

On Friday, the Aggies will be looking for a sweep of its in-state rivals, having already notched a victory over Utah on Sept. 7. Utah State hasn't beaten BYU in Provo since 1978.

In his first start for the Cougars, Hill completed 12-of-21 passes for 112 yards with two touchdowns and one interception, and rushed 15 times for 141 yards and a touchdown against Hawaii.

But it wasn't enough for Mendenhall to name Hill the starter this week.

"Taysom's doing his part," the coach said. "There's not as much history between he and I as Riley and I and our team. I'm a Riley Nelson fan, and believe in his leadership ability when he is healthy and when he's capable to play the kind of game that he can play. That will be the biggest decision, is how he's feeling."

Mendenhall said he doesn't know the timetable for Nelson's return.

"What we do know is, if he plays like we have been playing him, it won't get better, and if anything, it will get worse. Whether if one week will be enough for him to improve, we don't know that. It might be two weeks. We have been told that it will improve with rest and so that's what we're doing."

Asked if he played well enough to earn the starting job, Hill said, "I'm not sure. That's not my decision or anything like that. I won't get caught up in that right now."

One week after gaining just 200 yards of total offense against Boise State, BYU's offense erupted for 396 yards rushing against the Warriors. The Cougars passed for just 144 yards.

"We have some work to do in the pass game," Mendenhall said.

The Cougars shook up the offensive line against Hawaii, and it produced positive results. Braden Hansen moved from left guard to center, replacing Blair Tushaus, while Famika Anae started at left guard and Manaaki Vaitai started at right guard. Solomone Kafu also saw significant action.

"The shuffling at offensive line produced a culture change that was strong and apparent to me," Mendenhall said. "Famika Anae really did a nice job — super-physical out there. Braden Hansen did a nice job playing center. He added a little more poise and experience at that spot. Then Manaaki Vaitai stepped in at guard and did a nice job, as well as Solomone Kafu. It was fun to see some guys that are really hungry and eager to get a chance."

"They were physical," Hill said of the offensive line. "We started fast, and we were able to start fast because of the way our O-line was playing…. We were able to make some runs."

True freshman running back Jamaal Williams replaced injured Michael Alisa, who fractured his arm and underwent surgery on Saturday. Williams had 15 carries for 155 yards and two touchdowns.

"He has great vision. He's a really great athlete. We've seen that in his touches he's had up to this point," Mendenhall said. "Jamaal made the most of his opportunity."

Another backup running back, Paul Lasike, turned in a solid performance, rushing 10 times for 40 yards and two TDs.

"He's been a battering ram, beating us up defensively as a scout (team) running back," Mendenhall said of Lasike. "It was fun to see him come in and he has a really bright future."

Cougars and Aggies on the air:

Utah State (4-1) at BYU (3-2)

When: Friday, 8:15 p.m. MT.

Where: LaVell Edwards Stadium, Provo


Radio: 1160 AM, 102.7 FM