PHOENIX - Quarterback Kevin Kolb was either set up to fail, or just plain failed. It doesn't matter much now. He's no longer an Arizona Cardinal.
The team released him Friday morning, one day before he was due to receive a $2 million signing bonus.
The Cardinals added two more defensive players in free agency Friday, agreeing to terms with former University of Arizona and San Diego Chargers cornerback Antoine Cason, and former Raiders defensive end Matt Shaughnessy.
By releasing Kolb, the Cardinals saved cash and salary-cap space. Kolb was due to make $9 million in salary this year, and his release creates $7.5 million of additional cap space.
Cardinals general manager Steve Keim and coach Bruce Arians were not made available for comment. Kolb declined to talk at this time, and agent Jeff Nalley did not return messages.
Kolb was not cut solely because of money. The Cardinals, who paid Kolb $20.5 million over two seasons, gladly would have paid Kolb the money he was due if he had proven himself over the past two seasons.
But injuries caused Kolb, 28, to miss 17 of 32 possible games, and the Cardinals decided Kolb wasn't worth further risk.
This is the fourth consecutive off-season in which the Cardinals' priority has been to find a replacement for Kurt Warner, who retired after the 2009 season.
Drew Stanton, an unrestricted free agent from the Colts, signed a three-year contract Wednesday. As the roster stands, the former Michigan State QB is the favorite for the job.
But the depth chart is written in chalk. The team is expected to select a quarterback in the draft next month, and Brian Hoyer, who signed last December, may contend for the job.
The club is expected to keep either John Skelton or Ryan Lindley.
The trade that brought Kolb from the Eagles to Arizona in 2011 will go down as one of the more expensive mistakes in team history.
They traded cornerback Dominique Rodgers-Cromartie and a second-round draft pick in 2012 for Kolb, whom former coach Ken Whisenhunt and general manager Rod Graves deemed the best quarterback available that year.
Kolb threw for 3,124 yards in his two years in Arizona, with 17 touchdowns and 11 interceptions.
Both Cason and Shaughnessy are coming to Arizona under one-year contracts. The Cardinals have signed eight players from other teams since Tuesday, the day free agency started.
Cason hasn't missed a game in five seasons and was a starter the past three years. He was an All-American for the Wildcats and in his final season in 2007 won the Jim Thorpe Award, given to the nation's best defensive back.
A first-round draft pick by the Chargers in 2008, Cason has intercepted 12 passes in his career. He will contend for a starting job with the Cardinals, who now appear well-stocked at cornerback.
They signed Jerraud Powers, a former Colt, this week, and have Patrick Peterson, Jamell Fleming and Justin Bethel returning.
Shaughnessy started every game for the Raiders last season and finished with 3 1/2 sacks.
Shaughnessy had seven sacks in 2010 and is known as a solid run defender. He missed most of the 2011 season because of a shoulder injury.
Based on the current roster, Shaughnessy would be a reserve behind Darnell Dockett and Calais Campbell.
• Greg Jennings agreed to terms Friday with the Minnesota Vikings, leaving the Green Bay Packers to join their bitter NFC North rivals.
Jennings, 29, gives the Vikings the No. 1 receiver they so desperately needed after trading Percy Harvin to Seattle. Jennings played in only eight games for the Packers in 2012, finishing with a career-low 366 receiving yards.
• Miami signed tight end Dustin Keller and wideout Brandon Gibson on Friday to complete a much-needed upgrade of the receiving corps.
• Linebacker Keith Rivers signed a new one-year deal with the New York Giants.
• The Eagles acquired wide receiver Arrelious Benn and a seventh-round pick from Tampa Bay for Philadelphia's sixth-round choice this year and a conditional draft pick in 2014.
• San Diego agreed to a two-year contract with former New England running back Danny Woodhead.
• Oakland agreed to a free-agent contract with former Chicago linebacker Nick Roach.
• Jacksonville signed cornerback Alan Ball, running back Justin Forsett, defensive tackle Roy Miller and cornerback Antwaun Molden.