Vanden Bosch, 34, was entering the final year of his contract and would reportedly have counted $10.7 million against the Lions salary cap.
Brian McIntyre tweets that releasing Vanden Bosch will save the Lions $7 million in cash and $4.96 million in cap space.
His recent performance dropped off dramatically this season. Last year, he totaled 8 sacks while playing 777 snaps, but in 2012 he only tallied 3.5 sacks and was rated as the worst 4-3 defensive end in the league by Pro Football Focus.
Adam Caplan mentions that the Lions will consider shedding more salary and specifically lists LT Jeff Backus, QB Shaun Hill and TE Tony Scheffler as possibly being on the chopping block as well.