Astana’s Vincenzo Nibali started this year’s Giro d’Italia as the favourite to win his home country’s grand tour but so far, his numerous fans have had no reason to celebrate. Apart from a few ill-timed and unsuccessful attacks, the Sicilian has been in the limelight only when he has been dropped and lost time on the decisive stages. The reasons for Vincenzo Nibali's collapse at the Giro d'Italia remain enigmatic, with medical tests expected soon to reveal if he may be suffering from some kind of infection that has affected his form and extinguished his chances of winning the Giro.

In all likelihood, the final nail was hammered into Nibali’s coffin on Tuesday. His time loss in Andalo buried all hopes of success, and even the Italian press seems to have lost all hope.

In the Italian media, never afraid to criticize, Nibali’s problems have caused considerable debate and some criticism. The strongest attack, so far, came from former world champion Paolo Bettini in his daily column in the Gazzetta dello Sport. Yesterday, Bettini pulled no punches while analysing the reasons for Nibali's poor form.

Bettini rejected suggestions that Nibali has set too many objectives for 2016, and so is not at the top of his powers in this Giro d'Italia because he also targets the Olympic road race. He termed Nibali's decision to attack during Tuesday stage a 'tactical error' because he had perhaps failed to recover from his huge effort on Saturday's stage in the Dolomites to Corvara and his pain in the time trial on Sunday. He even questioned Nibali’s decision to switch from 172.5 to 175mm cranks for this season.

While  admitting that he did not know any details of Nibali's training Bettini went all out in his analysis.

"Observing Nibali at the Giro del Trentino just a few days before the start of the Giro d'Italia, you got the idea that he was behind with his form, that something wasn't right. It's true that it takes time assimilate altitude training but there seems to be something else," Bettini wrote. "Yesterday, Ulissi finished ahead of him in Andalo. I have a lot of respect for Diego but when Ulissi finishes ahead of Nibali, it means that he wasn't in a great condition.”

Bettini hinted that Nibali had not recovered sufficiently after his huge effort on Saturday's brutal stage in the Dolomites.

"On Saturday, he did a huge 50-minute effort, a kind of time trial and no doubt spent a lot of time over his threshold. After a long hard stage that lasted more than six hours, you pay for an effort like that. He clearly suffered in the mountain time trial, and then struggled to recover on the rest day. Because of all of these factors, it would probably have been better to stay hidden on the wheels and not attack yesterday, saving himself for the big mountain stages on Friday and Saturday."

Even Nibali's choice of crank came under scrutiny in Bettini's analytical piece.

"I don't understand why a rider who has won everything during his career decides to change his cranks at the age of 31. It seems a risk to me. Everyone knows that if you extend your reach your pedal stroke changes. Vincenzo has long legs, and so careful studies are needed before making a change. 172.5mm is the ideal length for him, with 175mm crank perhaps used for a flat time trial. I'm surprised by his decision and if it had been suggested to me, I'd have refused. You've always got to think carefully before changing your equipment; that's why I always used an old-style saddle. When you do change something, you've got to accept that I might not work out okay."

Interestingly, Bettini also indicated that rumours connecting Nibali to the Bahrain Cycling Projects, the delay in clarifying this situation and Nibali's reportedly strained relationship with Vinokourov at Astana may have influenced Nibali's form and concentration.

"Everyone knows that his relationship with Vinokourov is not idyllic and there have been reports of him leaving Astana going around for a long time," Bettini writes, raising lots of questions but giving few answers.

"I've got a feeling that there isn't the ideal ambient around him for him to do his best. I ask, is this Bahrain project solid? I don't know the details but I hope it is. However, any delays can get to you. I know, I was involved in the Alonso project that failed to happen. Vincenzo won the Tour of Oman and its right to ask how important was that win to give the Bahrain team project a push. But was it important for his build-up to the Giro d'Italia? Sometimes when a rider's contract is up, they feel under even more pressure to get results and this hasn't helped Vincenzo."