The backrower, who has also played hooker and halfback, came through the development system at his hometown club, making 73 appearances over five seasons, and still had a year remaining on his contract.
But at 23, Shorrocks, who played in 18 of Wigan's 32 matches this year, wants more regular rugby and reckons he'll have a better opportunity of getting it with the Red Devils, where he has signed a three-year contract to become the sixth close-season addition to a squad shorn of key duo Brodie Croft and Andy Ackers, who have joined Leeds.