Schalke midfielder Julian Draxler has bemoaned the injury problems blighting the club, questioning whether players are doing everything they can to be fit.
Jefferson Farfan, Sidney Sam, Leon Goretzka, Atsuto Uchida and Chinedu Obasi and Fabian Giefer have all spent time in the treatment room recently.
Although bad luck may be partly to blame, 20-year-old Draxler does not believe Schalke's problems are entirely down to that.
"We're all asking ourselves a bit where all these injuries are coming from," Spox.com reported the World Cup winner as saying on his return to preseason training.
"You've also got to ask yourself whether you're doing everything you can to be fit, whether you're getting the right nutrition or getting enough sleep.
"Other clubs are also going through strenuous preseason regimes, but they don't have players dropping like flies."
The midfielder said he was fit and raring to go after the World Cup in Brazil, telling his club's official website: "I'm fit and healthy.
"I spent a bit of time with friends in Ibiza and then visited the U.S. with my girlfriend. I tried to relax as much as I could, and I think I was pretty successful.
"It feels good to be back at Schalke. I was delighted to see my teammates again, and some of the new faces who are here too. I just can't wait for the coming season to start."