Nibali spent Tuesday’s rest day to scrutinize the 38km individual time trial parcours around Tarazona, using a scheduled rest day to prepare and recover for the next two weeks of the Vuelta. During the reconnaissance an insect, probably a bee, stung the Italian rider around the bridge of his nose.

Astana Pro Team Doctor Raquel Ortolano said the sting caused pain and inflammation, but did not result in an allergic reaction.

"Nibali is not allergic to bee stings, but nevertheless his eyes and face were swollen overnight, and he was experiencing a lot of pain. In the morning the inflammation was not better, and the pain was not less, but by the time he got to the start he began to improve," Ortolano said on the Astana website.

Nibali eventually finished Wednesday's time trial 1’25” behind stage winner Fabian Cancellara (RadioShack-leopard), but more significantly he took 1’39” out of race leader Chris Horner.

Nibali now leads the Vuelta a Espana by 33 seconds over Nicolas Roche (Saxo-Tinkoff), 46 seconds over Alejandro Valverde (Movistar) and 48 seconds ahead of Horner.