The John Jorgenson Quintet features Stephan Dudash on five-string viola, Gonzalo Bergara on rhythm guitar, Charlie Chadwick on bass and percussionist Rick Reed.
Martinez will also take goalkeeping coach Inaki Bergara and masseur Oscar Brau with him to join his new-look backroom team at Wigan but the two were out-of-contract at Swansea.
