By Julien Pretot
PARIS (Reuters) - A big question mark hangs over Vincenzo Nibali's form as the 2014 Tour de France champion targets a second Giro d'Italia title when the three-week race starts on Friday.
The Italian, who was disqualified from last year's Vuelta (Tour of Spain) after getting a tow from his Astana team car, has failed to impress since winning the Tour of Oman in February.
Nibali, one of only six men who have won all three grand tours, prevailed on the Italian roads in 2013 and he believes his experience will help him to succeed despite his recent poor form.
"My advantage compared to other riders is that I have the experience," said Nibali, who will be taking part in his sixth Giro.
Nibali picked Giro debutant and Movistar rider Alejandro Valverde as the man who could ruin his race.
However, the 2009 Vuelta winner, who finished third overall in last year's Tour de France, could have his Giro chances hampered by the tough weather conditions expected during the May 6-29 race.
"It's a treacherous Giro," said Valverde.
Team Sky will be hoping that Spain's Mikel Landa has what it takes to give them their first victory in a grand tour outside the Tour de France.
Landa, who joined from Astana this year, finished third overall last year after working for team leader and eventual runner-up Fabio Aru of Italy.
"That transition to a new team and expecting someone to perform at a really high level early on into a new term is a bit of a double whammy. It’s not a four-month goal," said Sky manager Dave Brailsford. "Our ambition with him is longer term. We think his ability to perform is huge. We would like to start that after four months racing but (transition) it’s a factor. But can he win the tour of Italy? Yes he can."
Fabian Cancellara of Switzerland is expected to don the coveted pink jersey as he will start off the ramp as the big favorite for Friday's opening time trial, where his main rival could be local favorite Tom Dumoulin.
Tour de France favorites Alberto Contador, Nairo Quintana, Chris Froome and Thibaut Pinot are skipping the race as they will be targeting medals at the Rio Olympics in August shortly after the conclusion of the Tour.
The Giro will start from Apeldoorn, Netherlands.
(Reporting by Julien Pretot, editing by Pritha Sarkar)