"It's been a great run but all good things must come to a end. Thank you Steelers Nation I will miss you all!" Harrison tweeted on Saturday morning.
The Steelers confirmed the transaction.
"James has played a major role in the success of this organization during his time in Pittsburgh," head coach Mike Tomlin said in a statement. "I appreciate everything he has done in my six years as head coach and wish him nothing but the best in the future."
Harrison's release does not come as a surprise as the 34-year-old is due $6.57 million in base salary with a $10.035 million cap number in 2013. The Steelers entered the week at about $3 million under their adjusted cap number of $124.4 million and releasing Harrison frees up $5.105 million in cap space this season.
The release of Harrison is not strictly about finances. Harrison's string of five consecutive appearances in the Pro Bowl came to end as the outside linebacker had six sacks in 2012, his lowest total since becoming a full-time starter in 2007.
In his 131-game career with the Steelers, Harrison had 64 sacks, 29 forced fumbles and five interceptions and was named the NFL's Defensive Player of the Year in 2008. In eight playoff games, Harrison had 6.5 sacks and an interception, which he returned 100 yards for a touchdown to close out the first half of the Steelers' 27-23 win over the Arizona Cardinals in Super Bowl XLIII.
With the Steelers moving on from Harrison, the team will look to 2010 second-round pick Jason Worilds to step up next season. Worilds has started 10 of his 42 games in the NFL and has posted 10 sacks, including a career-high five in 2012, and is entering the final year of his rookie contract.
As for Harrison, his ability as a pass-rusher will draw interest on the free-agent market and could have a new home quickly, perhaps before the new league year begins on Tuesday. The Baltimore Ravens could have interest as they're set to lose Paul Kruger to free agency. The New Orleans Saints, who are converting to a 3-4 defense on a full-time basis this offseason, Arizona Cardinals, Cleveland Browns and Indianapolis Colts are other possibilities for Harrison.
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