Mick Cook has made a return to York after being named assistant coach at the Huntington Stadium.
Cook has spent the past three seasons with Sheffield, helping them reach the 2011 Championship Grand Final.
He will work alongside player-coach Chris Thorman and existing assistant coach Mick Ramsden to help get the Knights prepared for their Northern Rail Cup campaign, which kicks off against Swinton on February 12.
Thorman said: “Training has been excellent so far and we have a good session planned for tonight to get straight back into things as we step up our preparations for the match against Keighley this weekend.
“Jason Demetriou (Keighley Player Coach) has said that the Cougars will be fielding a strong team so it will be a good test for both clubs.”