After more than seven months away from the races, Dolphin Jo is set to commence his bold bid for a third straight appearance in Australia's most famous race.

The five year-old Terry and Karina O'Sullivan trained galloper will start his Melbourne Cup campaign tomorrow in the Geoff Webb Plate (1600 metres) at Moonee Valley.

He has received top weight (59 kilograms) for the race, which will be the first hit out of a somewhat slow lead up to a hopeful run in the Cup.

Terry O'Sullivan said his preparation had started a long way out from the first Tuesday in November.

``We are a fair way out but we always planned to do a slow, long campaign with him because he had a good five months in the paddock,'' he said.

``He had a good rest, we think he is really well and he is in great order so he will race pretty sparingly from now until September.

``We will then get really serious and he will race a bit more solid after that.''

Dolphin Jo is likely to have around four weeks off after tomorrow's run before then tackling a 1700m race at Flemington. A 2000m event in early September is on the radar before the father and daughter training combination continues to gradually step the horse up in distance. A race such as the Metropolitan in Sydney looms as a target for the Stawell stayer, who may have to win a quality race in the lead up to secure a Cup start.

``There are quite a few races that will qualify him and he has to be on the verge anyway. If we can win one of those we are going to be around the mark,'' O'Sullivan said.

O'Sullivan said Dolphin Jo had matured and grown during his time in the paddock since November last year and believed the son of High Rent could improve on last year's fifth placing.

``I think he could probably run better because I am sure he is a stronger horse,'' O'Sullivan said.