Trainer Chris Waller will order a blood test to determine whether Patrick Erin is fit to run in the Lexus Stakes in a last-ditch effort to qualify for the Melbourne Cup.
Patrick Erin was scratched from Wednesday's Bendigo Cup because of a mildly elevated temperature.
The winner of the Group One Metropolitan Handicap needs to win Saturday's Lexus Stakes to force his way into the Melbourne Cup three days later.
Waller says he will get permission from stewards to take a blood test from the stayer on Friday to determine whether he can run on Saturday.
"He's very bright," Waller said.
"You wouldn't know there is anything wrong with him, if there is anything wrong with him.
"His feed bin has been licked clean every night and that's always the old sign of telling you that a horse is well.
"He had a slightly elevated temperature on Wednesday that caused a minor concern.
"It didn't go up to a limit where he needed any treatment so we just ran a precautionary blood (test) on him on Thursday.
"That showed an indicator that was up a little bit but certainly not of any huge concern.
"We're going to get permission to get another blood taken from him today and if that perimeter is coming down we'll be very happy. If it's going the other way, obviously it shows that there's an infection in his system."
"I would say this afternoon (Friday) once we get the blood results back we would know whether he's running or not.."
Patrick Erin is one of two horses Waller has entered for Saturday's Lexus, the other being Brimham Rocks who has finished second in his past three starts including the Metropolitan and the Herbert Power Stakes won by Melbourne Cup favourite Yucatan.
Waller already has three guaranteed Cup runners - Finche to be ridden by Zac Purton, Youngstar (Craig Williams) and veteran Who Shot Thebarman (Ben Melham).