Reports in the Spanish sports daily AS suggested Vinokourov had told the 2014 Tour de France champion he’d better start looking for a new team as disappointment over his form at this year’s race hit home.
“The balance of the first week and the first two days in the Pyrenees can only be defined as a catastrophe,” AS quoted Vinokourov as saying this week.
“Vincenzo takes a lot of money and asked for more,” he added.
However in a statement released after Stage 12, in which Nibali showed glimpses of the form that won him the yellow jersey 12 months ago, Vinokourov had nothing but good things to say about his Italian chief.
Stage 12 report
Rodriguez wins on Plateau de Beille
"There has never been a question that Vincenzo Nibali will leave the team at the end of the season - Vincenzo is doing very well in the team," the Russian said.
"Of course I am not happy when we don't win, as is the case with all team general managers. But I merely think that Vincenzo is not riding at his best level in this Tour.
"Nibali has a potential that is much better than his current place in general classification (9th at 7min 47sec).
"There is no problem between him and the team, and we have full confidence in him, contrary to what is being reported in the press."
As for the rider himself, he has kept reasonably quiet on his issues, claiming he has “no idea” on the causes of his lack of competitiveness.
AS claimed sources reported that Vinokourov told Nibali he should leave the team ahead of Stage 12, which if true clearly had the desired effect on his form for the day.
It is believed Vinokourov also sent Nibali a stern letter ahead of the Tour last year, demanding better form from the Italian. It worked then, with Nibali claiming four stages and the overall win.
Nibali reportedly earns around €4 million ($5.88 million) a season and while Astana would find it difficult to sack a rider on contract, it might opt to make life so uncomfortable for Nibali that he searches for a way out of that contract.
There could be pressure from higher up for Vinokourov as well. He was quoted as saying yesterday that Astana “must win one big tour this year”. With the Giro gone, and the Tour looking similarly unachievable, only the Vuelta remains for the Kazakh team to win.
Vinokourov said Nibali will also be asked to race there in search of the grand tour victory the team so desperately craves.
"We are going to do medical tests to determine the reason for his performance, and we also wish to see him race in the Vuelta a España this season to achieve a grand tour victory."
It’s been a troublesome year for Astana, with five of its riders testing positive for doping, including Nibali lieutenant Maxim Iglinskiy, who was suspended in October 2014 for EPO use having tested positive in the August prior.
In the hours leading into this Tour, Lars Boom defied rules set by the Movement for Credible Cycling when he raced despite testing for low cortisol levels. He has since abandoned with a fever.
As for Nibali, he claims to have "no idea" why his form has been so bad. He's also taken to ignoring Italian TV reporters baying for his blood for fear that he might be "rude".
"I'm sure the fans will understand," he tweeted after Stage 12.
