4. Joel Tompkins
Tomkins began his League career with Wigan in 2005 and outside of a short stint with the Widnes Vikings in 2007, played with the Warriors until moving to Saracens in 2011. While Tomkins initially struggled to adapt to union, but his form during the beginning of the 2013/14 season saw him earn an England cap against Australia in November 2013. Although he went on to make two further international appearances, he looked completely out of his depth and returned to league soon after.