American released on a free transfer after two years service to the club, and manager McCarthy praises the shot-stopper for his influence on and off the pitch
The American international is currently on duty in the Gold Cup, but won't be returning to the Premier League side.
He signed from Reading in 2009 and went on to make 44 appearances for Wolves, and the shot-stopper, who has a pilot's licence, was a popular figure at Molineux, demonstrated by fooling his team-mates into thinking he would fly them to a game at Newcastle on April 1.
Manager Mick McCarthy praised the goalkeeper. He told the club's official website: "Marcus has been fantastic for us - both in his performances on the pitch and influence off it.
"He was a great character to have around the place. It was a pleasure for all of us to have him in the squad for the last two years and we wish him all the very best for the next stage of his career."