Magnapal has come through a last-start scare in fine physical shape and trainer Terry O'Sullivan is hoping there are no mental scars.

The gelding, who runs at Flemington on Saturday, was lucky not to fall when Massiyn collapsed following an apparent heart attack as the field left the straight in a 2040m race at Moonee Valley on November 29.

Massiyn's rider Tom Sadler came off and suffered concussion when he fell while Magnapal's jockey Stephen Baster said he was lucky not to part company with his mount in the incident.

"It frightened him (Magnapal) quite a bit," O'Sullivan, who trains in partnership with his daughter Karina, said.

"He got the wind knocked out of him a bit.

"He also got posted deep, so hopefully we can forget that run as he didn't finish all that far away."

Magnapal finished 3-1/4 lengths eighth behind Schockemohle at the Valley and O'Sullivan said he had put in some solid work on the track since.

Melbourne premiership leader Dwayne Dunn rode Magnapal to win over 1600m at Sandown on November 19 and is back aboard in The Spotless Western Health Cup (2000m) on Saturday.

O'Sullivan believes a return to Flemington, a track where Magnapal has raced well at previously, will be a plus and the race will help the trainer determine whether the horse presses on to the Listed Bagot Handicap (2800m).

"His run at Moonee Valley was quite OK and he's come through it pretty good and we're hoping he'll run well on Saturday," O'Sullivan said.

"I don't think there are any mental scars out of that race at Moonee Valley.

"He's been pretty good and he's tough little horse.

"He likes Flemington and with Dwayne Dunn back on him, I think that's a big positive too."

"We haven't ruled the Bagot out but we'll work it out after he runs on Saturday," O'Sullivan said.