The 33-year-old striker has the left the club by mutual consent after repeatedly failing to lose weight and gain fitness.
The South-African was signed from Blackburn Rovers on transfer deadline day in 2010 and made only 14 appearances for the club in what proved to be an expensive mistake.
Suffering an injury on his debut, McCarthy sat out the next six weeks before returning to the club in an unfit state. He continued to provide the side with dross before Avram Grant finally decided enough was enough and promptly left his out the Hammers’ 25 man squad this year.
He has reportedly been paid around £1.5 million to be removed from the Hammers’ books.