Permit will figure in a gear change for Saturday's Lexus Stakes when he lines up as one of two Chris Waller-trained stayers chasing a Melbourne Cup berth at Flemington.

Waller has last-start Group One Metropolitan runner-up Kelinni in the Lexus (2500m) along with Permit who will have ear muffs re-applied and blinkers taken off in a bid to get him back to his best form.

"They both need to win to get into the Melbourne Cup and we're realistic about their chances," Waller said.

"Kelinni is certainly the form horse of the two and if he wins the race he deserves to be there (in the Melbourne Cup).

"And if he doesn't win the race he wasn't going to win the Melbourne Cup this year anyway."

Waller explained the gear change he's decided on for Permit is aimed at trying to get the stayer to relax during the race and save his energy for the finish.

Permit's past two starts have been an 11th in the Metropolitan and then a fifth in the City Tattersall's Club Cup, both over 2400m at Randwick.

"He's been disappointing," Waller said of Permit.

"His run in the Metrop was disappointing and his grand final last preparation in the Sydney Cup was disappointing.

"We haven't quite worked him out. I've put some ear muffs on him for Saturday and taken the blinkers off, just trying to get him to relax mid-race because for whatever reason he's just got nothing there to finish the race off.

"All the other signs are good. He's sound and he's well but something is stopping him in the race when the distances get further and it's certainly not his staying ability."

Waller has kept Kelinni ticking over since his second to Glencadam Gold in the Metropolitan on October 6.

"He's done a great job thus far and anything else is a bonus really," Waller said.

A field of 13 will contest the Group Three Lexus including Geelong Cup winner Gatewood who will be ridden by Glen Boss and is the early favourite.

The winner of the Lexus is exempt from ballot for Tuesday's Melbourne Cup.

Gatewood's one kilogram penalty for his Geelong victory was not enough to get him into the Cup field.