Premier trainer Tony Gollan's snap decision to book apprentice Jag Guthmann Chester for Sheiswhatsheis has delivered an unexpected bonus.

Sheishwhatsheis has been ridden by Gollan's apprentice Lani Fancourt at her past four starts for two wins.

Fancourt would have again ridden Sheiswhatsheis at Doomben in the Open Handicap (1600m) on Saturday but is injured.

She broke her arm in a fall at Murwillumbah last Friday and will be sidelined for several weeks.

Gollan was quick to check on Fancourt's condition and after making certain she was safe he realised he would need a new jockey for Sheiswhatsheis.

"I got straight on the phone and booked Jag who has been riding very well. What I didn't expect was that several highly rated horses would nominate and it pushed Sheiswhatsheis's weight down," Gollan said.

"She carried 57kg when fourth at her last start and was originally weighted in this race at 56.5kg. But with Jag's claim she will carry only 53.5 kg. It means we get in under the minimum and that is a bonus.". i

Gollan said Sheiswhatsheis had continued to impress him despite having had a testing campaign.

"She hasn't been any different and continued to do well around the stables,he said.

"She has won five races at the Doomben 1600 metres so she is in well at the weights."

Gollan said there was probably an unusual reason for Sheiswhatsheis's last start fourth at Doomben when favourite.

"I know it sounds strange but I don't think she liked the strong head wind down the back. If you look at the head on film she was getting her head on the side which was no help," he said.

Meanwhile, Gollan will test two promising three-year-olds Umberto and Splitz in the Three Year Old (1350m) on Saturday.

"The depth in this race and the three-year-old at the Gold Coast last Saturday has been very good so this will be a good test for them," Gollan said.

Splitz lived up to his two impressive trial wins with an easy victory at Ipswich at his first start.

"It is a step up in distance and class. But he worked well this week and he is out of a Zabeel mare so I am looking for him to get up to 1600 metres eventually," Gollan said.

Umberto has won his past two starts and Gollan believes he is holding his form.