MUR DE BRETAGNE, France (REUTERS) - Defending champion Vincenzo Nibali, who was banking on the opening block of racing to make his mark on this year's Tour de France, instead showed another sign of weakness on Saturday.
The Italian, who lost ground in the second stage after being trapped in a split of the peloton, finished 10 seconds behind the big guns on stage eight as they all finished together.
The Astana rider could not follow overall leader Chris Froome, Spain's Alberto Contador or Colombian Nairo Quintana in the final ascent, a 2km climb at an average gradient of 6.9 per cent.
"In the finale I didn't have good sensations. At the beginning of the stage I was fine but then in the final climb I could not respond to the accelerations," Nibali told reporters.
"It was an off day."
His sports director Giuseppe Martinelli looked worried after his protege fell one minute 48 off the pace of Froome.
"I don't understand what happened. We must think this was just an off day otherwise it will be a complicated Tour," the Italian said.
Martinelli is now hoping that Sunday's team time trial will give Astana the opportunity to regain some of the lost time.
"In the team time trial the team need to be perfect," said Martinelli.
"If tomorrow we are the team that we think we are we will ride a good time trial."
The team time trial is a 28km effort that finishes up the Cote de Cadoudal, a steep 1.7km ascent where the teams will need to stay as compact as possible as the time will be taken on the fifth rider to cross the line.
"We cannot afford any more mistakes," said Martinelli.