Colledge tweeted Thursday that after contract talks with Arizona, his time with the Packers has come to an end. Colledge started 76 games over five seasons for Green Bay.
"Thanks for the love guys," Colledge tweeted. "It truly breaks my heart to leave. It has been my greatest honor."
Colledge then embraced his new team, changing his Twitter profile photo to a Cardinals logo.
In a telephone interview with The Associated Press, agent Jeff Sperbeck confirmed multiple media reports that Colledge had agreed to a five-year deal with the Cardinals.
Sperbeck said the Cardinals were impressed with Colledge's combination of skill and "unprecedented" durability. And while Colledge had said in the past that he wanted to stay in Green Bay, Sperbeck said Colledge now is looking forward to the new opportunity.
"You can't look backward," Sperbeck said.
There was no immediate word from the Packers or Cardinals. Free agents may negotiate deals this week but are not permitted to sign with their new teams until Friday.
Green Bay still has decisions to make on other free agents, including wide receiver James Jones -- who may be attracting interest from division rival Minnesota -- and running backs Brandon Jackson and John Kuhn.
Jackson tweeted his own goodbye to Green Bay on Thursday night amid reports he is headed to Cleveland.
"I will have great memories of GB and will [always] be grateful," Jackson posted.
Jackson also thanked Browns fans for the "warm welcome."
Packers general manager Ted Thompson was careful to avoid discussing any free agents during his presentation at the Packers' annual shareholders meeting at Lambeau Field on Thursday morning. He skipped his usual position-by-position analysis of the roster, saying it wouldn't be "appropriate or fair" to talk about players who might not be there when the team reports to training camp Friday.
Thompson did assure the estimated 11,700 shareholders in attendance that the team intends to contend for another Super Bowl this season.
"We'll be fine," Thompson said. "We've got a good core of players with good heads on their shoulders."
The Packers announced the signing of 15 undrafted free agents Thursday, including Utah State wide receiver Diondre Borel; Delaware safety Anthony Bratton; Arkansas tackle Ray Dominguez; South Florida center Sampson Genus; South Carolina wide receiver Tori Gurley; Minnesota fullback Jon Hoese; Arkansas State safety M.D. Jennings; Temple linebacker Elijah Joseph; Middle Tennessee State linebacker Jamari Lattimore; Youngstown State cornerback Brandian Ross; Ohio State running back Brandon Saine; James Madison tackle Theo Sherman; Utah wide receiver and return specialist Shaky Smithson; BYU linebacker Vic So'oto; and Arizona State wide receiver Kerry Taylor.
The Packers also began to move on their draft picks. Agent Marc Lillibridge confirmed via email that fifth-round pick D.J. Williams, a tight end from Arkansas, had agreed to terms.
Earlier this week, the Packers told veteran linebacker Nick Barnett that he would not be returning. The team did not officially announce any cuts Thursday night, but veteran linebacker Brady Poppinga told the Green Bay Press-Gazette he was being released, and oft-injured defensive lineman Justin Harrell told the Milwaukee Journal Sentinel he was being released.