Willie Mullins accepts Boston Bob is likely to be inconvenienced by the ground in the Lexus Chase at Leopardstown on Sunday.
Last season's Punchestown Gold Cup and Melling Chase winner was a good second behind Don Cossack in the John Durkan three weeks ago, but his best form has, by and large, arrived on a decent surface.
And with conditions set to be relatively demanding at Leopardstown, Mullins accepts that could be an issue.
The County Carlow handler told www.wpmullins.com: "Boston Bob is in very good form but the ground has probably gone against him."
Jockey Ruby Walsh believes Boston Bob will need to be at his very best in a typically strong renewal of the Grade One over three miles.
He told the Irish Examiner: "He was second behind Don Cossack at Leopardstown last time but met interference at the third fence and was never travelling afterwards.
"I think he's improved for the run but he'll have to have as this is as good a renewal as there has been for years, and the winner will be a worthy winner."
Mullins also saddles last season's Cheltenham Gold Cup runner-up On His Own, who, like Boston Bob, is owned by Graham and Andrea Wylie.
The 10-year-old wears headgear in the Lexus following a couple of nondescript efforts since his fine run at Cheltenham in March.
Mullins said: "On His Own is getting a bit cute in his old age so we are fitting cheekpieces to see if that will help."
