Norman goes to Doncaster tomorrow needing just one more victory to complete a century of winners for the season.
The jockey has achieved the feat three times in the past but is on course to beat his previous best seasonal total of 130 achieved in 1994/5.
Williamson moved on to the 99-mark with a five-timer at Warwick on Saturday but has had to sit out Monday and today due to suspension.
The 31-year-old has five booked rides at the Yorkshire track, starting with Gingembre in the D.A.D Novices' Chase.
If Gingembre is unsuccessful he could reach the total aboard Jamaican Flight in the Tote Lady In Red Hurdle or Benvenuto in the Liberty Bells Novices' Chase.
However, his best chance of success appears to be on the Venetia Williams-trained Zahari who is likely to be vying for favouritism in the Canaliculatus Juvenile Novices' Hurdle.
His final ride of the day is Glamanglitz in the Dove Ings Handicap Chase.
