''To say I have been blessed is an understatement,'' Finnegan wrote Wednesday on Instagram. ''I am forever thankful. I have made my share of mistakes and had moments of glory. I even got into a fight in an NFL game.''
Finnegan was referring to his memorable 2010 brawl with Houston's Johnson while with the Titans.
Finnegan, 31, was an All-Pro with the Titans in 2008, but was slowed by an ankle injury last year with the Dolphins and said late in the season he might retire. He also played for the Rams in a nine-year career.
The Dolphins released him March 2.
AP NFL website: www.pro32.ap.org and http://twitter.com/AP-NFL