David Millar hopes his tortured past and uncertain present doesn’t spell demise for his immediate future.

The Scot is battling ghosts of his doping past and suffering through pangs of doubt over his form at the eve of the most important race of his career.

The repentant Saunier Duval-Prodir rider - who served a two-year ban for taking banned performance-enhancing products before returning to competition in 2006 – admitted he’s not at his best ahead of the 7.9km prologue to put the Tour de France into gear Saturday.

“I’m riddled with self-doubt. I don’t have the same confidence I normally do. I hope I can manage that,” Millar told journalists Friday. “I cannot predict what I am going to do. It’s an absolute abyss I am going into. It’s a bit disconcerting.”

He’s been unable to pinpoint the reason for the fatigue and lack of resilience that’s plagued him the past few months in the buildup to the Tour.

“It’s been about two months. It’s been horrible. I’ve never spent as long feeling so horrible on the bike,” he said. “It’s been very hard to pinpoint. It’s one of the banes of being an athlete. Sometimes it just doesn’t go right. You can spend weeks doing tests trying to find out what’s going on. Maybe I’ve overdone it about the Tour.”

Millar, who won the prologue in 2000, has been hyped as one of the favorites to win the prologue on home roads.

At least he’s had the chance to preview the 7.9km course. Because the course is in the heart of downtown London, officials won’t shut down the route until Saturday morning.

“For once, the Brits have a home-field advantage,” Millar joked. “As one of the few people to have ridden it, it isn’t very technical at all. I doubt there’s even braking in the corners. It’s not a course that requires a lot of recon runs. It won’t be won by your cornering.”

For the rest of his Tour, Millar said, “My dream is to win another stage. I’m not thinking about the GC.”

Millar said he holds a special place in the peloton as a reformed rider and doesn’t hide from what he views as a responsibility to speak openly about the need for changes within the peloton.

“My first objective is the racing, but none of us can escape the doping problems in cycling,” Millar said. “I have a special responsibility. I try to bring a positive element to it. We have to look to the future, but we cannot move into the future without dealing with the past and the present, and the sport has a lot to deal with. It’s slowly happening with people admitting to errors they’ve made.

“(Doping) is always on my mind. Not a day goes by without thinking about the big picture. We cannot forget that bigger picture. We have a special responsibility so the young guys coming through don’t have to deal with all of our baggage.”

Millar then defended beleaguered Saunier Duval teammate Leonardo Piepoli, who was suspended by the team after returning a “non-negative” test result at the recent Giro d’Italia. The veteran Italian tested high for salbutamol, an asthma medication. “I have a huge amount of respect and trust for him as a cyclist,” Millar said. “It’s very sad what’s he’s having to experience – and Petacchi too – who are undeservedly being punished.”

Another teammate, Iban Mayo, riding as Saunier Duval’s GC captain, looked tanned and sleek. The Basque climber was visibly overweight at the Giro d’Italia but told VeloNews he lost four kilos ahead of the start of the Tour.

Mayo is hoping for a return to form that saw him barnstorm to a stage victory at L’Alpe d’Huez and sixth overall at the 2003 Tour. He’s since struggled with health problems and crashes.

“The truth is the past three years, things haven’t gone as I would have liked. For reasons of crashes or illness, I couldn’t fulfill the Tour as I had hoped,” Mayo said. “My health is back and I have the motivation to return to the highest levels.”

Mayo left his longtime home at Euskaltel-Euskadi after seven years with the Basque team to sign on with Saunier Duval. He paid back the team with a stage victory at the Giro and he’s hoping for another stage win at the Tour.

“I don’t have the same pressure as I did at Euskaltel,” he said. “I’d love to win a stage again. We’ll see how things go in the GC. The motivation was never lacking.”