Nathaniel exit opens Arc way to Camelot

A contagion of ill fortune appears to be sweeping through Europe's top middle-distance horses. A day after Danedream was suddenly confined to Cologne by quarantine regulations, the leading British contender for the Qatar Prix de l'Arc de Triomphe yesterday joined the defending champion on the sidelines. Nathaniel is running a temperature and will not be able to run at Longchamp on Sunday.

It is a wretched dénouement to a story that had promised a very different sequel when Danedream and Nathaniel fought out a gripping finish to the King George VI and Queen Elizabeth Stakes at Ascot in July.

The Arc had already lost Snow Fairy to a setback last weekend, and on Monday connections of Danedream were abruptly stranded by an outbreak of swamp fever in her German training centre. These serial defections are making it very hard for the men round Camelot's table to resist the Arc. A final decision is expected after Aidan O'Brien has worked the Derby winner at Ballydoyle this morning.

A silver lining will also be perceived at Ascot, where opposition had seemed worryingly scarce for Frankel in the Qipco Champion Stakes on 20 October. Nathaniel is especially effective round Ascot and will presumably be diverted there if restored to health. Even second in so valuable a race could sway the trainers' championship, though that will seem the coldest of comforts for John Gosden right now.

Danedream, in contrast, cannot leave her home course for 90 days. Patrick Barbe, racing manager to Teruya Yoshida, duly accepted that there was no point even confirming her entry. "Nothing can come in and out for three months," he said. "That situation at the moment is final and binding. If the race was in two weeks, they might have found a solution, but with time being so short it has proved too difficult."

An intriguing factor in the Camelot decision is the dilemma over his rider. Camelot is set to carry 8st 11lb, 2lb below the reluctant minimum of O'Brien's son, Joseph. The Ballydoyle trainer has already stated that Camelot would need a new jockey, barring the removal of a limb, but his patrons may consider one or two of the alternative solutions almost as drastic.

With Ryan Moore set to be claimed for Sea Moon, they may well turn to one of the stable stalwarts. Admittedly Seamus Heffernan had an unhappy experience on So You Think in last year's race, but Colm O'Donoghue reliably seizes every chance he is given and is now seasoned at this level.

Otherwise John Magnier and his partners at Coolmore could conceivably contemplate burying past differences with Frankie Dettori, whose availability belies his status as one of the all-time masters of Longchamp, a notoriously challenging circuit. Dettori has long served Coolmore's great rival, Sheikh Mohammed, and even expressed contrition after accepting the chance to win the 2005 St Leger for O'Brien on Scorpion. But the sheikh would surely owe Dettori greater indulgence this time round, after promoting young Mickael Barzalona to share the Italian's role at Godolphin.

Turf account

Chris McGrath's Nap

I'm Back (7.40 Kempton) Finished best of those held up behind a subsequent Group winner last time.

Next best

Shestheman (8.10 Kempton) Shaped much better back on this all-weather surface last time, and now ready for the longer trip.

One to watch

A comeback win for Eagles Peak (Sir Michael Stoute) at Goodwood last week suggests he will soon make up for lost time at Group level.

Where the money's going

Sea Moon is 10-1 from 14s with Ladbrokes for Sunday's Arc.