The Astana team, invited to the Giro d?Italia at the last minute, suffered a further setback when two of their riders were struck down with illness in the run-up to the start on Saturday.

Astana rider Dmitry Muravyev was forced to pull out of the team when he developed a stomach infection earlier in the week. He was replaced by Lance Armstrong?s former domestique Benjamin Noval.

But Noval has been forced to relinquish his place, after contracting a similar illness. Noval underwent tests this morning, but it was decided he was unfit to start the race. Swiss rider Steve Morabito is being flown in at the last minute to replace Noval.

There are concerns that race favourite and Tour de France champion Alberto Contador, who shared a room with Noval, could also be stricken with the illness.

Astana were given little time to prepare for the Giro, after it was announced only last week that they would be on the start line. And now their preparation has been knocked further.