Sir Michael Stoute is expected to make a decision by the weekend on whether unbeaten filly Leocorno will run in the Ribblesdale Stakes at Royal Ascot.

The Pivotal filly was eased down when winning impressively at Sandown last month but was ruled out of both York's Musidora Stakes and the Epsom Oaks after puncturing a foot.

Peter Reynolds, manager of Ballymacoll Stud, who own the filly, said: "The Ribblesdale looks a very hot a race - possibly as hot as the Oaks - and we will know if she runs there a little bit later in the week. Leocorno has only run twice so she is still inexperienced but all is well.

"The only certainties are that Patkai will run in the Ascot Gold Cup (18 June) and Tartan Bearer goes in the Prince Of Wales's Stakes (17 June). They are both in good shape."

Patkai is best-priced at 4-1 with Ladbrokes as he attempts to stop Yeats completing a four-timer in the Gold Cup and Reynolds hopes he will improve from his last run at Sandown, when sent off an odds-on favourite, only to finish five lengths adrift of Geordieland.

Reynolds said: "He appeared to hang a bit last time but he was alright after the race and he likes Ascot. Pilsudski was beaten every time he ran there but he still ended up a champion."

Glass Harmonium, who was sixth to Black Bear Island in York's Dante Stakes, will take a drop in class to run in the 10-furlong Hampton Court Stakes (18 June), rather than the Group 2 King Edward VII Stakes.

Reynolds confirmed: "It is 90 per cent certain that he will run in the Hampton Court. We just felt that this trip would suit him better and he also drops into a Listed race."