O'Brien playing Arc waiting game with St Mark's Basilica

Aidan O'Brien will give St Mark's Basilica as much time as possible to prove his fitness for the Prix de l'Arc de Triomphe at ParisLongchamp on October 3. 

The three-year-old's return to action following his victory in the Irish Champion Stakes at Leopardstown earlier this month has been delayed due to an ongoing infection that initially flared up during the build-up to August's Juddmonte International at York. 

St Mark's Basilica's success at Leopardstown was his fifth Group One victory in a row and further underlined his credentials as the best of his generation. 

He is a general 12/1 shot to add another triumph in next month's Arc but there are no guarantees the Siyouni colt will head to ParisLongchamp at all, with O'Brien confirming he and his staff are exercising caution due to the infection which is on the front of his near hind joint. 

O'Brien said: "He's fine. We built him back up into full work after Leopardstown but when we did he was just a little bit sore on the cut that he got on the way to York. 

"The cut opened up a little bit so we just had to pull back off him for a little bit. Where it was on the front of his near hind joint and as he flexed it kept opening and closing and we couldn't stitch it or do anything. 

"He's back doing gentle canters so we'll see over the next five to seven days how that goes and how much it settles down. We'll just have to wait and see which way it's going to go. 

"He can go anywhere really, a mile or a mile-and-a-quarter doesn't seem to matter to him. All options, everywhere, are open to him. We just have to get him back perfect and go from there." 

St Mark's Basilica is eventually expected to head off to stud given his world-class pedigree and success at Group One level, with O'Brien acknowledging it will be up to the colt's owners as to when that day will come. 

He added: "That's up to the lads [owners Ballydoyle], they make all those calls,. When the time comes for him to go to stud, he will be one of the most important to do so since Galileo." 

Even if St Mark's Basilica does not make it to the Arc, O'Brien, who last won the race with Found in 2016, is expected to be well stocked for the Group One showpiece, with Snowfall and Love almost certain to run. 

Both fillies are on the comeback trail following defeats in their most recent outings, with Snowfall coming up short in the Prix Vermeille at ParisLongchamp, while Love was beaten by the Paddy Twomey-trained La Petite Coco in the Blandford Stakes at the Curragh.