English stayer Duretto is in doubt for the Melbourne Cup after pulling up lame after a gallop at Werribee.

Racing Victoria stewards said Duretto would undergo a bone scan at the University of Melbourne Equine Centre on Tuesday to determine why he was lame in his left fore leg after a gallop on Saturday.

Duretto is restricted to box rest until the scan.

The Andrew Balding-trained Duretto finished fourth in the $5 million Caulfield Cup last Saturday week and was at $17 in a Melbourne Cup market on Sunday.

"The results of the scan will assist Mr Balding, in consultation with his veterinarians and RV veterinarians, to determine whether Duretto is in a suitable condition to be a final acceptor for next week's $7.3 million Melbourne Cup," RV stewards said.