Hayes is stalling on a new deal to stay at Glanford Park, and is eager to earn hismelf a pay rise.
He has been watched by scouts from various Championship and League One clubs, with Brighton and Nottingham Forest also linked with a move.
But Ritchie is the first to confirm an interest in Hayes.
He said: "Paul is a good player and one who we have been looking at throughout last season.
"We have been monitoring him at Scunthorpe but there is nothing to add other than he is one of the players we have been watching."