Arizona quarterback Kurt Warner tosses a pass during a Sept. 23 game against Baltimore. A season-ending injury to Matt Leinart makes Warner the starting quarterback for Sunday's game against Carolina.

Tempe, Ariz ? Kurt Warner knows how to persevere.

Whether it’s defying the odds to go from NFL castoff to Super Bowl MVP or hanging in there with a good attitude after losing his job to a rookie – twice.

Now Warner is back. The 36-year-old quarterback will start for the Arizona Cardinals against the Carolina Panthers on Sunday, replacing young Matt Leinart, who is out for the season because of a broken collarbone.

Even though he’s been playing behind Leinart, and helping the second-year pro without complaint, Warner believed all along that he was good enough to start.

“I think I’ve proven that through the preseason and even through the time that I’ve played in the regular season that a lot of people would see me as a starter,” he said.

Even though he wasn’t starting, Warner has seen considerable time on the field as the quarterback when coach Ken Whisenhunt goes to a “no-huddle” offense, a fact that Leinart didn’t like.

From the start, Warner showed a knack for grasping the offense Whisenhunt brought with him when he took the job this year.

“For whatever reason, it made sense to me,” Warner said. “It was easy to pick up for me, and I could visualize what I was supposed to do on a lot of plays. When you can do that early on in an offense, you can kind of take control of it and gain confidence in it.”

Still, as expected, Warner was on the sideline when Arizona opened the season. He did what he could to mentor Leinart and tried to stay ready if needed.

As he settled in to his role as veteran backup, it was easy to forget Warner’s unprecedented rise from obscurity to stardom not so long ago.

Warner signed with Green Bay as an undrafted free agent out of Northern Iowa in April 1994 but was released four months later. Three seasons with the Iowa Barnstormers of the Arena Football League followed before he was signed as a free agent by the St. Louis Rams the day after Christmas in 1997.

He played 10 games in 1998 for the Amsterdam Admirals of NFL Europe, then saw action in the Rams’ final game of that season.

Then came an unbelievable 1999.

Warner got the Rams’ starting job and took off from there. He broke virtually all the franchise passing records and was the league and Super Bowl MVP in the process. He passed for a Super Bowl-record 424 yards in leading St. Louis over Tennessee.

Two years later, Warner got the Rams to the Super Bowl again and won his second NFL MVP award.