Tomkins started the first match of the 2006 season at , in a match against the Catalans Dragons which the Wigan Warriors lost, 38–30. He was demoted to the bench for the second match of the season against the Leeds Rhinos. After 17-minutes he was brought from off the bench and scored a try with his first touch of the ball to give the Wigan Warriors a 4–0 lead. The Wigan Warriors went onto lose the match, 16–24. In February 2006, Tomkins agreed a contract extension with the Wigan Warriors which would keep him at the club until 2008. He started from the bench for the next two matches against the Huddersfield Giants and the Salford City Reds, but he was dropped to the Academy just shortly after. He later returned to the squad when he was named on the bench for the Challenge Cup fourth round match, against the Wakefield Trinity Wildcats on 2 April 2006.