John Gosden is worried about the forecast rain for Racing Post Trophy favourite Foundation at Doncaster on Saturday.
The unbeaten colt beat his main market rival for the Group One in Aidan O'Brien's Deauville in the Royal Lodge last time out.
He is favourite for next year's Investec Derby and will be looking to put the seal on a tremendous season for Gosden and Frankie Dettori.
However, if more rain than is forecast falls Gosden may need to think about running him.
"It's autumn ground, it's sticky and dead," the Clarehaven handler said from Doncaster on Friday.
"There is some rain forecast. If it does turn very soft that would worry me. This horse has got a good turn of foot.
"If it turned into a slog that would concern me, but let's see how much rain comes.
"A bit of ease would be OK but if we got a lot of rain and went entirely the other way we would have to have a think.
"There are a couple of horses in there who would love that kind of ground - Deauville and Mengli Khan.
"They both won in heavyish ground. They would be the ones I'd have to watch out for."
Foundation is owned by Highclere Thoroughbred Racing, run by Harry Herbert, who was involved in a Racing Post Trophy winner before. The Royal Ascot Racing Club-owned Motivator prevailed in 2004 before claiming Derby glory the following summer.
Foundation's owners include former Manchester United manager Alex Ferguson, who is expected to make the journey to Town Moor this weekend.
"It's more than exciting for everyone involved, we've got a good team going to Doncaster and we'll see whether he's up to winning a Group One at this stage of his career," said Herbert.
"It would be amazing if he can end the season as an unbeaten Group One winner, that would be fantastic, but Group Ones are always very hard to win.
"Our jockey is in brilliant form and John's horses have just been in incredible condition all year.
"Whatever happens this weekend, we know we've got a very nice horse to look forward to."
Aidan O'Brien has a formidable hand in his bid for an eighth Racing Post Trophy triumph.
The trainer's son Joseph gets the leg-up on Royal Lodge runner-up Deauville, who has three-quarters of a length to make up on Foundation on their Newmarket clash.
The master of Ballydoyle also saddles the Seamie Heffernan-ridden Johannes Vermeer, last seen finishing fourth in the Prix Jean-Luc Lagardere at Longchamp, and Beresford Stakes winner Port Douglas, the mount of Emmet McNamara.
Johannes Vermeer is part-owned by the China Horse Club and the head of international racing and breeding, Michael Wallace, told the club's website: "The Racing Post Trophy is never an easy race to win but Aidan knows what it takes to win an event of this stature, his record is testament to that.
"Johannes Vermeer has shown ability in his short career to date and is deserving of this opportunity.
"It will be exciting to see how he measures up in a race that always attracts a quality field of runners."
Hugo Palmer has enjoyed something of a breakthrough season, enjoying numerous big-races success with Classic heroine Covert Love, Gifted Master and Galileo Gold.
The Newmarket handler has an interesting contender for this prestigious event in the form of Mengli Khan, who having shaped with promise on his Rowley Mile debut last month, got off the mark in some style at Nottingham two and a half weeks ago.
Palmer said: "He is a very big horse, but he has a high cruising speed and travels very well in the soft ground.
"He is plenty strong enough and has got a remarkable engine.
"He is a high-class horse who will be much better as a three-year-old."
Tony Curtis has won twice from three starts for Richard Hannon, most recently landing the Listed Stonehenge Stakes at Salisbury in August.
James Ramsden of owners Chelsea Thoroughbreds said: "We can't work out what ground he wants.
"He won a Listed race easily at Salisbury on good to soft ground, yet he was a close-up third at Newmarket in the Superlative Stakes when they broke the track record. He's like most Rock Of Gibraltars, he'll go on anything.
"He's looked like he wants further and we think he will do next year, probably 10 furlongs, but we trust Richard Hannon to make the right decision regarding that.
"We were going to put him away for the season after Salisbury, but this race can cut up and he doesn't have much to find on the official ratings."
Peter Chapple-Hyam has trained two previous winners, with subsequent Derby hero Authorized winning the 2006 renewal when it was run at Newbury.
This year the trainer saddles Newcastle scorer Marcel.
He said: "He's a horse I've always liked. He's a big horse, so we just gave him some time after his last run and waited for the backend of the season.
"We thought about running in the Autumn Stakes, but decided to wait for this and we'll find out if we're good enough or not."
