Guineas hope Ten Sovereigns spearheads Newmarket treble for back form O'Brien & Son

A virus laid the all-conquering Co Tipperary yard low during high summer.

But Ten Sovereigns' success-and earlier victories for Fairyland in the Group 1 Cheveley Park Stakes and Mohawk in the Group 2 Royal Lodge Stakes - proved O'Brien’s string hale and hearty for the autumn challenges that lie ahead.

The son of American sprinter No Nay Never is 7-1 for next year's 2000 Guineas, but his trainer fears one mile will stretch the colt’s stamina.

"He's a very fast horse - a lot of speed," said O’Brien. "He won't get much further than a mile if he gets a mile."

Fairyland initiated the 'double double' - O’Brien took both top-level juvenile tests with US Navy Flag and Clemmie in 2017 when edging out The Mackem Bullet by a neck in the Cheveley Park Stakes.