The 38-year-old quarterback announced his retirement yesterday after a dozen years in a league that at first rejected him, then revered him as he came from nowhere to lead the lowly St. Louis Rams to two Super Bowls.

Then, as if going from stocking groceries to winning NFL MVP awards wasn’t improbable enough, Warner was written off as a has-been and rose again to lead the long-suffering Arizona Cardinals to the Super Bowl.

A man of deep faith who carried a Bible to each postgame news conference, Warner walked away with a year left on a two-year, $23 million contract, knowing he still had the skills to play at the highest level.

“It’s been an amazing ride,’’ Warner said. “I don’t think I could have dreamt it would have played out like it has, but I’ve been humbled every day that I woke up the last 12 years and amazed that God would choose to use me to do what he’s given me the opportunity to do.’’

Warner had one of the greatest postseason performances ever in Arizona’s 51-45 overtime wild-card victory over Green Bay Jan. 10, but sustained a brutal hit in the Cardinals’ 45-14 divisional-round loss at New Orleans six days later.

The Cardinals signed Warner to a one-year contract in 2005 largely because no other team would give him a chance to be a starter. His opportunities over the next two years were scattered and even when coach Ken Whisenhunt took over in 2007, Warner was the backup to Matt Leinart. But when Leinart went down with an injury five games into the season, Warner got his chance. He started 48 of the remaining 49 games of his career.

“I’ve played 12 years, I’m 38 years old, and I believe I was playing at as high a level now and over the last two years as I was playing when I first got into the league,’’ he said. “That’s something I’m proud of.’’

Blessed with an uncanny throwing accuracy, Warner leaves the game with a legacy that could land him in the Hall of Fame even though he didn’t get his first start until he was 28.

In a comparison with the 14 quarterbacks to make the Hall of Fame in the last 25 years, Warner has a better career completion percentage, yards per pass attempt, and yards per game. Only Dan Marino, Brett Favre, and Peyton Manning have more career 300-yard passing games.

In 124 regular-season games, Warner completed 65.5 percent of his passes for 32,344 yards and 208 touchdowns. He and Fran Tarkenton are the only NFL quarterbacks to throw for 100 touchdowns and 14,000 yards for two teams.

Warner, who grew up in Cedar Rapids, Iowa, and played at the University of Northern Iowa, ranks among the career leaders in a variety of passing statistics. No player in NFL history reached 10,000 yards passing in fewer games and he tied Marino as fastest to reach 30,000. He has the top three passing performances in Super Bowl history and his 1,156 yards passing in the 2008 playoffs broke the NFL record of 1,063 he set with St. Louis in 1999.