Glyn Schofield has been unsuccessful in his appeal against a five-week riding ban over his handling of Number One Gun in a race at Randwick.

The matter was heard on Thursday by the Racing NSW Appeal Panel which dismissed Schofield's appeal but varied his penalty from five weeks to four.

The reduction was given in recognition of the top jockey's previously unblemished record under that rule.

Schofield will ride at Randwick on Saturday when his mounts include Midsummer Sun in the Listed Australia Day Cup.

He will begin his suspension on Sunday and can return on February 23, a day after the Apollo Stakes meeting at Randwick.

Schofield was suspended by stewards for failing to give Number One Gun all reasonable and permissible chance to win a 1400m race on the Kensington circuit on December 20.

The horse finished second to Rowie with stewards critical of Schofield's efforts to restrain the gelding, particularly between the 600 and 400 metres.

Number One Gun was timed to run the first 1000m of the race 0.02 seconds outside track record time for the trip.

His first 800m was run in a time equivalent to 20 lengths quicker than is average for 1400 metre races since the Kensington track was reopened in October.

Schofield is yet to decide whether he will lodge a further appeal.