"So much fun, so many memories & friendships forged in Green Bay. Ups & downs, wins & losses! Even a XLV championship. Forever grateful," Bishop wrote on Twitter.
Bishop, who missed the 2012 season with a torn hamstring, didn't participate in any of the Packers' organized team activities or their mandatory minicamp because of the injury.
The Packers have three veteran inside linebackers set to earn a starter's salary this season, two of whom had their contracts written after Bishop's injury. Brad Jones, re-signed in March, will make at least $4.2 million this season. A.J. Hawk agreed to a restructured contract that will pay him $3.6 million. Bishop, meanwhile, is set to earn $3.96 million. Together, the trio counts $12.164 million against the 2013 salary cap.
ESPN Milwaukee had reported last week that Bishop's release was likely unless he agreed to restructure his contract or the Packers were able to find a trade partner.
He tore his right hamstring in the team's first preseason game last year.
Bishop, 28, had a career-high 115 tackles and five sacks in 2011 in just 13 games. He has 292 tackles, nine sacks, eight forced fumbles and an interception in 69 career games, all with the Packers.
Information from ESPN.com NFC North blogger Kevin Seifert was used in this report.