On April 5, 2006 the Devil Rays designated Cash for assignment, and after clearing waivers, reported to AAA Durham where he spent the entire 2006 season. Cash signed a minor league contract with the Boston Red Sox on January 24, 2007. On November 2, 2007, Cash opted for free agency after refusing to accept an outright assignment to AAA Pawtucket. On December 13, 2007, Cash resigned with the Red Sox to a minor league contract with an invitation to spring training. On July 1, 2010, Cash was acquired by the Boston Red Sox for Ángel Sánchez after Jason Varitek went on the disabled list.