07/08/2013 12:05 EDT | Updated 09/07/2013 05:12 EDT

Froome set to be offered better protection from Sky teammates as he bids to win Tour de France

SAINT-NAZAIRE, France - Chris Froome's Sky team manager vows the star rider will never be left exposed again in his bid to win the Tour de France for the first time.

Froome successfully defended the yellow jersey on a ferociously tough mountain stage on Sunday and will wear it when the race resumes for Stage 10 on Tuesday following a rest day.

The fact Froome had to defend the jersey alone on Sunday's ninth stage — because all of his teammates had been left behind — offers hope to rivals like two-time champion Alberto Contador and Andy Schleck that Sky may be vulnerable. If they can isolate Froome again further on in the race, he will be more tired and may not be able to respond.

"We've learnt some lessons, valuable lessons, to take into the rest of the race," Sky manager Dave Brailsford said Monday. "But I'm not going to spell it out. I'm not going to go into the details of the changes we're going to make."

Froome's key teammate is Richie Porte, a 28-year-old Australian who won the Paris-Nice stage race in March. He was unable to help Froome on Stage 9 and badly wants to make amends.

"It was absolute war," he said. "Am I going to have another bad day like that? I hope not."

Contador, the Tour winner in 2007 and '09 who was stripped of his title the following year for doping, is already looking ahead to getting another crack at Froome in the mountains on Sunday.

"I will try and do something," Contador said. "If you don't think you can succeed then you never will. So we have to take a few risks."

Sunday's 15th stage is the next big climbing trek and features a 20.8-kilometre (12.9-mile) ascent up to Mont Ventoux. A few days later, riders face three straight days of mountain torture in the high Alps.

"Throughout my career I've found my best form in the third week," the 30-year-old Contador said.

The Spaniard takes heart from winning the Spanish Vuelta last year, a race in which Froome finished about 10 minutes behind in fourth overall.

"People can speculate and look at my previous performances however they like, but I look at that Vuelta in that I was running on fumes. I was in survival mode," Froome said. "If people want to make comparisons that's up to them, but I don't feel I was at my best."

Rather than looking back, Contador should focus on the immediate future — notably Wednesday's time trial.

"It's a very flat time trial and that is a disadvantage for me," Contador said about the 33-kilometre (20.5-mile) circuit.

Froome finished second to Tour winner Bradley Wiggins in the time trial last year and is considerably faster than Contador, who may be able to limit the time gaps this time because the dash from Avranches to Mont-Saint-Michel is relatively short.

Given the dominant way Froome is riding, he can take a big step toward winning the Tour if he extends his overall advantage after the time trial.

Spanish rider Alejandro Valverde is 1 minute, 25 seconds behind Froome. Contador is 1:51 behind in sixth, while Schleck is four minutes back in 15th place, and Evans is 4:36 adrift in 16th.

None of them will want to look in the history books.

Valverde but was a massive 7:20 slower than Froome in last year's 53.5-kilometre (33.2-mile) time trial; Evans was 4:28 slower. They again face the prospect of losing significant time to Froome.

This is the 100th edition of the Tour and also the first since Lance Armstrong was stripped of his seven straight titles from 1999-2005 for serial doping.

Froome has said twice so far during the race that he is riding clean. Contador again repeated that he has never doped, even though he tested positive for the banned drug clenbuterol.

"Naturally people are going to ask questions in cycling," Froome said. "Whenever there are great performances they have been linked to doping in the past, so naturally now we're bearing the brunt of a lot of those questions."

Contador, who lost his 2010 title to Schleck, has always denied doping and said: "You can believe what you want. But the only thing that I can tell you is that I have always practiced cycling clean."

Froome would not be drawn on Contador's comment, other than saying: "there definitely do need to be questions asked about performances in the past."

Tuesday's stage is a 197-kilometre (122-mile) route from Saint-Gildas-des-Bois to Saint-Malo and is made for sprinters.