Hugh Bowman has suffered a blow in his bid for a come-from-behind Sydney jockeys' premiership win at Warwick Farm on Wednesday.

Bowman goes into the final Sydney metropolitan meeting of the racing season 2-1/2 wins behind rival Nash Rawiller but he will have only four chances to overcome the deficit.

One of his mounts, the Chris Waller-trained Pinot Gris, was among 14 scratchings for the seven-race midweek card on Wednesday morning.

Pinot Gris' scratching comes after Tuesday's withdrawal of another Bowman mount, leaving the defending titleholder with just four Warwick Farm rides.

But all may not be lost for Bowman with at least two of his mounts, Msongari and Syncopated among the favourites to win their respective races.

Rawiller's book of rides has also been reduced with Empress Elect's scratching from the first race leaving him with six mounts.

In a month of racing where he has so far ridden 21 city winners, Rawiller leads Bowman by 75 to 72-1/2.

His mounts on Wednesday include Sir Berus, favourite to win the last race.