Knowles arrived in South Yorkshire from Featherstone Rovers at the start of last season and only missed a handful of matches, as he became a regular for Mark Aston's side.
He arrived as a back-rower but was played in the front-row and he certainly impressed.
Undoubtedly one of the biggest metre makers in the squad, Knowles is a tough cookie to say the very least.
A fine player in a ferocious pack.Player Information
Date of Birth: 31/07/1993