Gap - Tour de France leader Chris Froome admitted he is concerned about
Movistar pair Nairo Quintana and Alejandro Valverde, his closest challengers.
Colombian Quintana is second overall at 3min 10sec with Spaniard Valverde
third at 4min 09sec.
But it was Movistar's tactics on Wednesday's 17th stage from Digne-les-Bains
to Pra Loup that most impressed Froome.
While he was left alone without team-mates on the final climb to the finish,
Quintana and Valverde had two other Movistar riders for company.
"They rode a very good race tactically, also putting riders in the
early breakaway today (Wednesday) so they could drop back once they'd crested
the penultimate climb (and help their leaders)," said Froome, 30.
"It was a very impressive ride by them to have numbers in the finish
However, despite Froome being all alone, Tejay Van Garderen had quit the
race through illness and Alberto Contador was two minutes back down the road
Reigning champion Vincenzo Nibali was still in Froome's group but the
Italian is more than eight minutes back in seventh place.
Froome said the only people he needed to worry about were Quintana and
"For me the main concern was following Alejandro Valverde and Quintana
-- those two were the only real two I needed to watch in that group," the
"In essence, it made my job easier than if I had to think about eight
or nine guys - there were only two to focus on."
Froome, though, admitted he was surprised by the tactics not only shown by
Movistar, but also Contador and Nibali.
The attacks started in the first 50km of the race before they increased as
the stage progressed.
"It does give a taste of what to expect these next three days, there
are three tough stages to go and my rivals are going to push me all the way to
the finish, and they're also battling out amongst themselves for a podium
Team Sky leader Froome said his rivals were running a risk by attacking so
far out as they could blow a gasket and harm their own chances.
"I wouldn't say necessarily that it's desperation but I can see that my
rivals are definitely going to take bigger risks," he added.
"I definitely feel as if attacking towards the beginning of the stage,
that's a pretty big risk.
"If they do get away they're going to spend 100km up the road using
"We're definitely seeing an all or nothing approach from the general
classification contenders but they could pay for those efforts over the next
But as the likes of Contador have no interest in finishing second, Froome is
resigned to keep defending.
"Alberto Contador lost more time in that final descent with his crash
and you can only expect him to attack in the next few stages."