Aidan O'Brien has taken the first step towards an assault on the Melbourne Cup after Yeats entered quarantine over the weekend ahead of a possible trip down under. The Coronation Cup winner went into quarantine on Saturday evening and may yet become a first runner in Australia for Ireland's most powerful racing stable.

"He's gone in on the basis that if he isn't there then we can't consider the Melbourne Cup," said O'Brien yesterday. "We also have the option of the Canadian International for Yeats and a decision will be taken closer to the time. But Australia is definitely a possible."

Dermot Weld's 1993 success with Vintage Crop opened up Australia's greatest race to international competition and Media Puzzle three years ago completed a remarkable Weld double in the Melbourne Cup.

Australia is new territory for O'Brien, however, and if Yeats does travel to Flemington rather than Toronto for the Canadian International a week beforehand it will bring an intriguing new element to the race that stops a nation. However, one who will not be travelling is Irish St Leger winner Collier Hill who is suffering from a bout of arthritis.

Vinnie Roe, runner-up last year and fourth to Media Puzzle in 2002, is also an intended Irish starter in Melbourne in what could be the final start of his magnificent career.

Of more immediate concern to O'Brien is a Group One week that culminates in the Prix de l'Arc de Triomphe on Sunday. The Ballydoyle trainer said yesterday that no decision will be taken on Scorpion's participation in the Arc until later in the week although all the indications are that Kieren Fallon will end up riding Hurricane Run.

O'Brien is set to have major involvement in some of the other Group One prizes at Longchamp over the weekend with Horatio Nelson a likely starter in the Grand Criterium and the Moyglare winner Rumplestiltskin leaning towards Sunday's Prix Marcel Boussac over a mile rather than Thursday's Cheveley Park Stakes at Newmarket.

Horatio Nelson is one of three Ballydoyle entries in Friday's Middle Park Stakes and O'Brien said yesterday: "We have Art Museum and Ivan Denisovich in the Middle Park and the plan is for Horatio to possibly go to France. I would say the Boussac is more likely for Rumplestiltskin than the Cheveley Park."

The three-day Goffs Orby Sale begins this morning but plenty of Irish racing professionals will also be keeping an ear out for news of today's scheduled Horse Racing Ireland meeting where a decision on whether or not a 10 million grant will be given to Dundalk for a new all-weather track is likely to be taken.

A detailed submission has been prepared for HRI's directors to examine the details of a project that has generated plenty of controversy over the last six years.

Much of that controversy has been due to the location of the proposed new facility which has been criticised for being not central enough for both racing fans and professionals. At the moment the Dundalk track is scheduled to be opened in early 2007 but a HRI grant will be vital to plans going ahead.

The number of horses declared to run at Ballinrobe this afternoon is putting pressure on the stable space available at the track and those with horses in the last two races are being asked to time their arrival to the Mayo course as late as possible. That won't matter to Johnny Murtagh who travels west for the first four races starting with Michael Halford's Faynita in the six-furlong handicap. This one has ground to make up on Bahrain Gold from Listowel last week and the job may be too much.

The bet of the day could come in the concluding mares maiden hurdle where the consistent Mount Grace can finally break her duck over flights. Only half a length was the margin when Mount Grace was runner-up to Charyan at Listowel during last week and Barry Geraghty steps in for the ride this time.

Dermot Weld was in double form at Cologne yesterday, taking Listed races with Burren Rose and Society Hostess. Burren Rose claimed the IVG EuroSelect-Preis over a mile and a half while Society Hostess came out on top in the eight-furlong Preis des Porsche Zentrum Köln.