Connections of Mutakayyef face an anxious few days as they wait to discover the extent of the injury sustained by the six-year-old as he completed back-to-back victories in the Fred Cowley MBE Memorial Summer Mile at Ascot on Saturday.
The Sea The Stars gelding, trained by William Haggas, will be scanned once the swelling on his leg has eased.
"We're not going to know until we get scans this week, but it doesn't sound very good," said Angus Gold, racing manager to owner Sheikh Hamdan Al Maktoum.
"It looks like ligament problems around the base of the sesamoid and all William was able to tell me was until we get the scans on Monday or Tuesday we won't know.
"There is nothing we can do. We'll just have to wait. Hopefully it won't be too bad.
"We have to wait until the swelling goes down to assess the damage.
"He's been a fabulous horse for us."
As well as the pair of Group Two triumphs, Mutakayyef has performed with great credit at the top level, finishing third in last year's Juddmonte International at York and the Woodbine Mile, as well as second in the Queen Anne Stakes at Royal Ascot last month.
