Pericles has tuned up for the Group 1 Underwood Stakes with a gallop at Caulfield.

A start in a Group 1 race at Caulfield could determine whether Godolphin galloper Pericles stays in Melbourne or heads back to Sydney for the remainder of the spring. 

A last start winner of the So You Think Stakes at Moonee Valley on September 7, Pericles will be one of the favoured runners when he chases his maiden Group 1 win in the Underwood Stakes (1800m) on Saturday. 

Pericles galloped at Caulfield on Tuesday morning in preparation for Saturday's race, and Nacim Dilmi, representing trainer James Cummings, suggested the race could be spring defining. 

He said the likely scenario was for Pericles returning to Sydney for the Group 1 Epsom Handicap (1600m) at Randwick on October 5 and remain for The Five Diamonds (1500m) at Rosehill on November 9. 

However, Blake Shinn, who rode Pericles in his win at The Valley last start, said the Group 1 Cox Plate (2040m) at The Valley on October 26 should be looked at. 

"The 1800 metres is probably as far as we want to go with him," Dilmi said. 

"Blake Shinn did mention the Cox Plate after his win at Moonee Valley, but every time we have stepped him to the 2000 metres, he doesn't seem as effective. 

"He's entered for the Cox Plate, but it's unlikely at this stage. 

"It will be a hard race on Saturday, but we will get a bit more information. 

"If he hits the line and keeps going and gives a strong indication that he could go a strong 2000 metres, we can have a good look on Saturday and work it out from there." 

Dilmi said Pericles had trained on well from his win at The Valley where the gelding switched off late in the contest. 

"From the 600 metres onwards, it looked like he was going to win a long way out," Dilmi said of Pericles' win in the So You Think Stakes. 

"But Blake said he stargazed a little in the last furlong, that's why he was so far in the front, but the margin wasn't as much. 

"Looking at the nominations, it's not going to be an easy Group 1 for him on Saturday, but he's definitely going in the right direction to hopefully win his first Group 1."