Fanene was cut by the New England Patriots yesterday with the designation of "failure to disclose physical condition", a new option implemented by the NFL this year. Fanene has missed the last 13 practices because of his knee injury that might require arthroscopic surgery. Fanene did pass a physical before signing his contract, though.
The Patriots picked up Fanene as an unrestricted free agent on March 20, 2012 and gave him a $3.85 million signing bonus after spending his entire career with the Cincinnati Bengals. It's quite possible that the Patriots will go after that signing bonus. Since Fanene seems healthy enough to play football this season, it's possible that trying to grab that bonus back was the primary reason for this move.