In three years as Rudy Carpenter's backup, Arizona State quarterback Danny Sullivan sometimes wondered if he had come to the wrong school.

Who could blame him?

Carpenter finished his career by starting 43 straight games, and with each passing week Sullivan wondered if his time would come.

"I told my family members, 'I'm not going anywhere. I'll stick it out if I have to,' " the 22-year-old Sullivan said after practice this week. "But at the same time, that was the toughest three years of my life, just sitting there going, 'Why can't I be the starter?'

"It was just like, 'God, when are we going to get to 2009?' " Sullivan said.

The wait is over. Sullivan, a 6-foot-4, 242-pound senior from Los Gatos, Calif., will make his first start on Sept. 5 against Idaho State.

"This has made me a more patient person," Sullivan said.

Sullivan knew it would take a miracle _ or perhaps a disaster _ for him to play much as a freshman. The next year, though, Sullivan said he began to improve in practice, and that's when he began having doubts about his decision to sign with ASU.

"I was like, 'What would happen if I had went somewhere else? What would it be like?' " Sullivan said. "At times, you think about that. But at the same time, in the back of my head, I was like, 'This is where you're supposed to be. This is your time. Just stick it out and good things will come to you, hopefully.' "

Quarterback has long been a strength at ASU, which has produced such stars as Danny White, Jake Plummer and Andrew Walter.

Carpenter left ASU with 81 touchdown passes, four fewer than Walter, the school's all-time leader. Carpenter also ranks third in Pac-10 history behind Walter and USC's Matt Leinart, who leads with 99.

Carpenter's departure created a quarterback derby among Sullivan, sophomore Samson Szakacsy and true freshman Brock Osweiler.

Szakacsy is more mobile than Sullivan, and Osweiler is said to have the most promise of the bunch. But Sullivan is the only one who has taken a snap in college, and his steadiness and experience tipped the scales with coach Dennis Erickson and his staff.

"He understands what we're trying to do, and that's so important," Erickson said.

Last year, Sullivan played in every game, completing only 15 of 43 passes (34.9 percent) for 151 yards, and he had one touchdown pass and two interceptions. For his career, Sullivan is 40-of-87 for 409 yards, with three touchdowns and three interceptions.

Erickson said Sullivan had learned much as Carpenter's understudy.

"If you spend time really watching and study and really observe the guy that's playing in front of you, you can learn a lot," Erickson said. "And he's done that. He's a student of the game, and that's what separates him right now from the other quarterbacks."

Carpenter could produce spectacular results when plays broke down, but he was also erratic. Sullivan offers reliability.

"He hasn't made any mistakes," Erickson said. "He's not going to throw it in a crowd, turn it over. He's been very careful with the ball. I call it playing within yourself, not trying to make plays that you can't make."

Sullivan is charged with helping to revive a program whose aspirations often outpace its achievements.

Carpenter led the Sun Devils to a share of the 2007 Pac-10 title. But after opening last year ranked 15th in The Associated Press Top 25, the Sun Devils lost to UNLV at home, launching a six-game losing streak that matched a school record.

The Sun Devils finished 5-7 and lost to their only ranked opponents, Georgia and USC, by a combined 55-10. With that embarrassment still in their minds, Sullivan said he sensed a renewed commitment among his teammates during offseason workouts.

"We had a different attitude going into this year, because 5-7 does not cut it anywhere, no matter where you are," Sullivan said. "So we've had a way different mindset than years past."

It's a cliche that the backup quarterback is often the most popular man on campus, and when Carpenter struggled last season, fans called for Sullivan to start.

Now Sullivan hopes the same fans will be patient with him.

"All I hope is our fans can back me for this year," Sullivan said. "I'm sure they're waiting for Samson or Brock to take me over. But I just hope they give me a chance."