They'd be on the hook for the guaranteed portion, which according to rotoworld:
8/21/2009: Signed a five-year, $17.6 million contract. The deal includes $15 million guaranteed. Another $7.4 million is available through incentives based on playing time and sacks. 2010: $395,000, 2011: $757,500, 2012: $1.12 million, 2013: $1.4825 million, 2014: $1.5 million, 2015: Free Agent
http://www.rotoworld.com/content/playerpages/player_contract.aspx?sport=NFL&id=5177
I agree, this was a move because he is not good enough to get on the field and contribute. Even on special teams.