Hayes quit Glanford Park for the Yorkshire side last summer, and was instrumental as they won promotion via the League One play-offs.
The former Norwich trainee scored the winning goal at Hull on Tuesday, and Ritchie reckons Hayes and strike partner Marc Richards will score plenty of goals.
He said: "Both Marc and Paul will be so much better for their goals at Hull.
"It will do them the power of good to get a goal apiece."