The horse rated the biggest Melbourne Cup threat to Incentivise remains under a fitness cloud on the eve of final acceptances for the $8 million race.
UK stayer Spanish Mission was found to have swelling in the right foreleg and was inspected on Friday morning before being re-examined several hours later.
The second test revealed the swelling had subsided but there are concerns about an infection underneath the horse's skin.
New Zealand stayer The Chosen One and Caulfield Cup flop Delphi have been passed fit to race after they were re-examined on Friday.
Racing Victoria says Spanish Mission will undergo a further test on Saturday to prove his fitness.
"RV veterinarians will re-examine the horse tomorrow to determine its suitability to accept for the Melbourne Cup ahead of the acceptance deadline," an RV statement said.
As it stands, Spanish Mission and last year's winner Twilight Payment are the only internationals left in Tuesday's race after Away He Goes suffered a setback in training.
Trained by Andrew Balding, Spanish Mission has brought imposing northern hemisphere formlines to Australia.
They include a Gold Cup placing at Royal Ascot and a narrow defeat behind Stradivarius, the UK's premier stayer, in the Lonsdale Cup at York in August.
On the strength of that record, Spanish Mission had met with solid betting support to beat Caulfield Cup winner Incentivise but has drifted since the injury scare was revealed.
