Physically and mentally, Hawai'i's quarterbacks are just fine.

Colt Brennan aggravated his already injured right ankle, but it's not serious (the physical) and his replacement Tyler Graunke appeared to have won the fans back (the mental) with a much-improved performance in the No. 15 Warriors' 52-37 Western Athletic Conference win against Utah State last night at rainy Aloha Stadium.

The two combined were 28 of 58 for 465 yards with four TD passes. Brennan was 19 of 25 for 219 yards with one TD, a 22-yarder to Davone Bess, while Graunke was even more on target at 9 of 11 for 246 yards and three TDs: a 72-yarder to Jason Rivers, a 36-yarder to C.J. Hawthorne and 20-yard shovel pass to David Farmer. He could be the only backup with a shot at taking weekly conference honors.

But the 33,398 were silenced just before the half, when Brennan was pressured on a three-yard pass to Hawthorne. When the pile disassembled, he was still down on the field.

"My ankle got tucked up underneath," Brennan said. "I just tweaked the same ankle (that was already hurt). It just hurt really bad at first."

As he left the field, Graunke entered. But the silence didn't last long. On his first play, Graunke dropped a perfect pass to Bess to the Utah State 1, drawing cheers, and probably sighs of relief.

"It felt good" admitted Graunke about the crowd support compared to when he started two weeks ago against Charleston Southern, when pockets of boos could be heard. "If I can get the crowd back on my side, that's awesome."

His performance was a complete turnaround from that game. He completed his first nine passes. OK, so his last two were off. In fact, the last one was intercepted. But by then, the damage was done because of his three TD passes and TD run.

Graunke's performance enabled the Warriors to not push Brennan through his injury. There are still six games to come.

"I definitely could've pushed it, but we were waiting to see how the game played out," Brennan said. "When Tyler came in and was doing really well, it was best to sit me down and rest up my ankle."

Brennan opened UH's first series of the second half, completing 1 of 3 passes for minus-five yards. Even though the Aggies scored on their ensuing possession to pull to 31-20, Graunke returned for the next series, wasting little time, completing 2 of 2 passes, the second being a 36-yard TD to Hawthorne.

Quarterbacks coach Dan Morrison said Brennan started the second half to see how his ankle would respond.

"He felt at halftime that he could go," Morrison said of Brennan. "But he tweaked (the ankle) again."

Morrison said the Aggies started trying to attack Brennan's ankle.

"In the second half, a lot of players were trying to wrap that leg," Morrison said.

But Graunke delivered when his team needed him.

"He was real confident in his throws," Morrison said. "He just had a good feel for where people were and what he needed to do. He slipped a little bit on the last one, but he ended up with some big yardage, touchdowns and completions."

Graunke apparently wanted to demonstrate he was his own man. After his long completion to Bess to the USU 1, Brennan suggested from the bench that he run the option. But Graunke had other ideas.

Graunke was stopped for no gain on first down as the seconds ticked away. He called the option on the next play, going to his left, and sticking his arm with the ball over the plane. It took an officials' review before the TD was called.

"I told him, 'gimme the ball, gimme the QB sneak, I can get the ball in,' " Graunke said. "And, uh, didn't work. So we ended up running the option he wanted to run."

Hawthorne, who led all UH receivers with nine catches and was second with 116 yards, said Graunke didn't miss a beat in his relief work.

"Don't give me the credit," Hawthorne said. "Tyler played great. I'm very impressed by the way Tyler played. I'm always impressed by the way Colt plays, but I think he (Graunke) has a lot to build on and he's moving in the right direction."

Reach Stacy Kaneshiro at skaneshiro@honoluluadvertiser.com.