Coach Ken Whisenhunt won't say so officially, but Matt Leinart's strong preseason performance certainly seems to have erased any doubt that he's Arizona's No. 2 quarterback.

"You've got to give Matt a lot of credit because he has faced a tremendous amount of criticism about his work ethic, about other things in his life besides football," Whisenhunt said. "He's worked very hard to focus on being a better quarterback, and it's shown up in this preseason."

Leinart has been sharp from the beginning of training camp, and it's carried over to the preseason games.

He has completed 38-of-62 passes for 517 yards and three touchdowns, with one interception. Most of his stats came last Friday against Green Bay, when he threw for 360 yards and three scores in the second half to lead a rally against the Packers' reserves. Arizona cut a 38-10 lead to 38-37 before a two-point conversion try failed and the Cardinals lost 44-37.

"Obviously I'm still learning but I just feel so comfortable out there, knowing where to throw the football," Leinart said after Tuesday's practice. "That's how it's kind of been all camp. It's nice to practice well and then it shows up in the game. I feel really good, really confident out there."

Brian St. Pierre signed a $1 million contract with the promise that he'd get a chance to be the No. 2 quarterback behind Kurt Warner. But St. Pierre struggled in the first two preseason games, then missed the Green Bay game with a sore back. He also will miss Thursday night's preseason finale at Denver.

Leinart, meanwhile, has made the most of his opportunities against the opponent's reserves.

"If anything I think it's just another year in the offense," he said. "You learn and the more you're around things the easier it gets. Also, just the preparation. I've prepared harder, studied harder, worked out harder, just everything."

Leinart said he never worried about the competition with St. Pierre.

"Honest to God, I did not think about it," he said. "Last year I thought about it way more, going against Kurt, it was just more pressure I think. But this year I knew my role going in, I know my position. Whether they said whatever they said, I knew where I was and what I was able to do if I just worked, and that's what I've done."

Leinart's offseason preparation included mixed martial arts workouts under Jay Glazer.

"That was the mental part of it for me mostly," Leinart said. "Physically it was tough but it's more so developing that mental toughness. Not that I wasn't mentally tough, but it was kind of developing the toughness that nothing can break you. That's what you have to have as a fighter, because those guys are nuts."

It's an attitude that transfers well to a quarterback, he said.

"For a quarterback there are a lot of ups and downs," Leinart said. "There are a lot of bad plays or interceptions or whatever. You have to bounce back and just continue to go forward no matter what happens."

Leinart lost the starting job in a battle with Warner in training camp last year, then watched as the veteran quarterback had a Pro Bowl season in leading the Cardinals to the Super Bowl. Whisenhunt said he believes Leinart learned a lot from that experience.

"He's said this, and maybe that's part of it," Whisenhunt said, "that playing behind a quarterback that had as good a year as anybody, and seeing what it takes from a preparation standpoint and a work standpoint, that's always something that makes you grow up."

Even though he was a Heisman Trophy winner at USC and a No. 1 draft pick who has 16 NFL starts in his three pro seasons, Leinart has never complained publicly about his demotion. He's also shrugged off suggestions, usually made from afar, that he is an NFL bust.

"Listen, as much as he's been hammered, that's a credit to him," Whisenhunt said. "He hasn't (complained). He's just stayed true and worked."

Warner, who initially got the No. 1 job when Leinart broke his collarbone five games into the 2007 season, has a string of 31 straight starts. It's a streak that can't go on forever, especially when the quarterback is 38 years old.

"I think everything happens for a reason," Leinart said. "I think my time is coming soon. I feel it. I just want to be ready when it happens."