SCHOTEN, Belgium (VN) — German Marcel Kittel dominated the sprints in the 2014 Tour de France, but has struggled to even race in the 2015 season due to a virus and a slower-than-expected recovery.

Team Giant-Alpecin’s top sprinter had to pull out of the Tirreno-Adriatico stage race and skip his title defense in Wednesday’s Scheldeprijs. His hope now is to be recovered in time for the Tour de France, which begins July 4 in Utrecht, Netherlands, but it is a “slow” process.

“May 1 in the Tour of Yorkshire? It’s very difficult to say when he can return,” team doctor, Anko Boelens told VeloNews.

“We want to have him fit again so it’s not going to be too hard on him when he’s racing again. We are constantly evaluating it.

“He’s trying to train as normal as possible, but the intensity is not what you’d expect from someone who is ready to race and to win.”

The German with blond hair won the Scheldeprijs the last three years — 2012, 2013, and 2014. Last year’s win set him up for his best season yet with two stage wins in the Giro d’Italia and four in the Tour de France.

His best day was his first day of racing this 2015 season. He won the non-categorized People’s Choice Criterium two days ahead of the Tour Down Under on January 18.

After returning from Adelaide, Australia, he had a blocked nose, cough, and missed six to seven training days. In the following Tour of Qatar stage race, he ended up making it worse.

Kittel had to take one and a half weeks off his bike and restart after Qatar while doctors struggled to determine what type of virus afflicted him.

“The virus is gone. There’s no medicine you can take, the only cure is time,” added Boelens.

“He’s training and improving, but it’s a slow process. The virus wasn’t influenza or Epstein-Barr, but ever since then, he had to take a big step back. He’s improving, but it’s a slow process. We are not taking any risks.”

Team Giant remains hopeful it will race the Tour de France with Kittel in shape to face sprinters like Mark Cavendish (Etixx-Quick-Step) and Wednesday’s Scheldeprijs winner, Alexander Kristoff (Katusha).

Ideally, he will return to race the Tour of Yorkshire on May 1, the Tour of California, and the ZLM Toer ahead of the Tour. The race program hinges on his training and recovery.

“He’s training but not on a program and he cannot do it every day,” explained sport director, Rudi Kemna.

“It’s a little bit up and down how he is feeling. He’s in training, but not what we would normally like, and he’s not ready for races. It’s a shit thing when you can’t do the training that you want.”

Giant may rely on Milano-Sanremo winner John Degenkolb, and general classification riders Tom Dumoulin and Warren Barguil, but with Kittel, the German team has had the most success.

“Marcel Kittel is an important rider for us, that’s clear,” added Kemna.

“He brings us a lot of success, together with the whole team, but Marcel is the sprinter and he is important.”