Imported stayer Tres Blue will not be a part of Gai Waterhouse's bid to win the Melbourne Cup for the second time in as many years.

A starter in last year's Melbourne Cup won by retired stablemate Fiorente, Tres Blue is out of the spring because of minor fractures in his left fore knee.

Waterhouse told stewards in NSW and Victoria on Wednesday of Tres Blue's setback.

Tres Blue arrived from France in time for the 2013 Melbourne Cup but he finished a long way down the course behind Fiorente.

An autumn campaign was kept to two starts on rain-affected tracks when the five-year-old was well beaten in the George Ryder Stakes and JRA Plate.

On the strength of a promising European record which included French Group Two and Group Three wins over 2500m and a German Derby placing, Tres Blue was purchased by a syndicate closely connected to Tulloch Lodge.

Waterhouse trains the Melbourne Cup favourite The Offer, this year's Sydney Cup winner which has been entered for a Randwick barrier trial on Friday.

The Offer has been at the top of Melbourne Cup betting since trouncing Opinion and Sertorius in the Sydney Cup at Randwick in April.

He is a son of Montjeu which won two of his six starts in Ireland for Aidan O'Brien.