Image 1 of 4 Marcel Kittel (Katusha-Alpecin) (Image credit: LaPresse - Ferrari / Paolone) Image 2 of 4 Marcel Kittel (Katusha-Alpecin) waves to the crowd (Image credit: Getty Images) Image 3 of 4 Peter Sagan and Marcel Kittel show off their threads (Image credit: Twitter) Image 4 of 4 Marcel Kittel poses for a selfie (Image credit: Getty Images)

Marcel Kittel's long-time agent, Jörg Werner, has blasted rumours about the German sprinter's performance problems. At the same time, he told Cyclingnews that “we are totally at a loss as to why he is not at his usual level.”

Former pro Jürgen Van Den Broeck, now a commentator for Belgian media source Sporza, said that he had heard reports that Kittel was "not busy with his profession" and was "drinking too much beer and wine.”

“What shall I say? What Van den Broeck says is the greatest nonsense that I have ever read,” Werner said in a mail to Cyclingnews. “Where does he have this from?

"Perhaps it would have been a good idea for him to speak with Marcel before making such claims publicly. I think that he only wants to make himself important with these statements. I find it really bad that people get an audience with such unfounded claims.”

Kittel commented Thursday afternoon on Twitter, writing, "Always easy to beat a man when he's on the ground. I'm facing a difficult period and I'm thankful for everyone who is supporting me now. To those people making headlines on my cost now: enjoy your minute of fame!"

Kittel has the Katusha-Alpecin team's only win of the year from the Trofeo Palma, but he has struggled over the past month. Following on a relatively dry 2018, the lack of results is concerning for a rider who has won 14 stages of the Tour de France.

Werner defended his rider, saying, “Marcel lives totally professionally! I have worked with him for a long time and we have an absolutely honest relationship with each other. I would be the first to take him to task on it if it was otherwise.”

Whatever the problem is, “it is definitely not because of his attitude to the sport! And the team knows that too. At the moment we are also totally at a loss as to why he is not at his usual level.”

He ended his email with a jab at Van Den Broeck, saying, “I believe that it is perfetly normal that one can't always win. Jürgen van den Broeck certainly should know that well enough himself."

Werner runs the TeamSpirit agency in Erfurt, Germany. The agency represents numerous German cyclists, including Kittel, Tony Martin, Maximilian Schachmann, and Kristina Vogel.