Rogers says it will be tough for Contador to do the Giro d'Italia-Tour de France double, but "if there's one person that can do it, it's Alberto".

The Canberra cyclist will be Contador's right-hand man as the Tinkoff Saxo leader attempts to win his third Tour, which starts in Utrecht, Holland, on Saturday.

If Contador does win the yellow jersey, he'll become the first since Marco Pantani in 1998 to do the double.

Rogers, 35, is contracted to Tinkoff until the end of 2016 and he said his decision about whether to keep riding will depend on his  enthusiasm for the sport.

"[If] I still feel ready to make the sacrifices to get up and [do the] training and follow the rigorous life to a level where I can compete well and that also means there needs to be a great leader within that plan, like Alberto Contador," he told Fairfax Media.

"If you sacrifice yourself every day, it's entirely likely that you will have great success. I need that leader or champion to fulfill my goals."

Contador said last year he wanted to ride all three grand tours - the Giro, Tour and Vuelta a Espana - in one season.

He won last year's Vuelta, saluted again in this year's Giro and is hoping to make it a grand tour grand slam at this year's Tour.

Rogers was unsure whether Contador could then push on to ride in this year's Vuelta as well and  a decision couldn't be made until the 2015 Tour had finished.

The Aussie veteran said the Tinkoff team would need to ride a smart race for Contador to win, given his  main contenders have built their year around the Tour.

Rogers listed Team Sky's 2013 Tour champ Chris Froome, Nairo Quintana (Movistar) and last year's winner Vincenzo Nibali (Astana) as Contador's main contenders for the general classification title.

"We've taken a different approach to the other teams, where they're coming in a lot fresher - we've got at least five guys [in Tinkoff] that are doing the double ... so that means we have to ride very conservatively in the first part of the race," Rogers said.

"No one's done [the double] since 1998, Pantani was the last, but if there's one person that can do it, it's Alberto, but saying that it's no easy feat and we're going to have to have very good legs and great harmony between the whole team."

Rather than use racing as part of his preparation, Rogers has basically trained alone - just as he did for the Giro earlier this year.

He felt it was the way the sport was heading, with the UCI planning to reduce the number of races resulting in   riders competing  less   and training more.

Rogers had a brilliant 2014, winning two stages in the Giro and saluting for the first time in a Tour stage as well.

Contador's broken leg last year opened the way for that Tour stage win, but Rogers was unsure whether he would get the chance to chase solo honours in this year's edition.

His main job is ensuring Contador has the best chance of finishing in yellow, but he said he was in similar form to last year.

"First and foremost we want the overall win, so that will probably involve me staying by Alberto's side as long as possible," Rogers said.

"But saying that, if opportunities do arise and I have the freedom of going in search of some of those breakaways like I did last year, I'll be the first to put my hand up.

"First and foremost, it's the overall victory that really eludes us and is the one we really want."

TOUR DE FRANCE

Saturday: Stage one, individual time trial, Utrecht, Holland, 10pm. TV Time: Live on SBS One.