Trainer Aidan O'Brien admits he has concerns about the soft ground for the Lloyd Williams-owned Order Of St George in the Gold Cup at Royal Ascot.

Last year's Irish St Leger winner dominated his rivals on his return to action in the Saval Beg at Leopardstown and is favourite to continue his winning spree in the Cup over 4000 metres on Thursday (Friday AEST).

"Order Of St George handles a dig but going that far, you wouldn't want it too soft," O'Brien said.

"He is a class horse and was just ready to run when he ran in Leopardstown and hopefully he will have progressed from then.

Jockey Pat Smullen has no worries about Melbourne Cup runner-up Max Dynamite who is the second favourite despite a first-up third at Sandown.

"I'm really looking forward to him. Order Of St George is going to be a warm favourite, but Max Dynamite is a very good horse," Smullen told At The Races.

"His run in York last year was very good and obviously his run in the Melbourne Cup was very good. If he brings that form, he'll be very competitive.

"The Sandown race was a very messy race and I don't think you saw him in a true light at all.

"A true-run race will be ideal for him and hopefully the run at Sandown will leave him spot-on for Thursday."