Borussia Dortmund head coach Jurgen Klopp has admitted he is sweating over the fitness of some of his key players before this weekend's Ruhr derby against Schalke.
Poland international midfielder Jakub Blaszczykowski has been ruled out with an ankle injury, while 20-year-old German attacking-midfielder Mario Gotze, who has been in impressive form for both club and country, is also sidelined.
Meanwhile, there are concerns over left-back Marcel Schmelzer, who sustained a back injury in Germany's clash with the Republic of Ireland, and Turkish midfielder Ilkay Gundogan.
"I have to be patient," Klopp told the official club website.
"After [Gotze]'s 25-minute cameo on Tuesday, I received a text message from him, which said: 'My thigh will heal soon'."
"Ilkay has trained yesterday for the first time since two weeks with the team," adding, "it actually looked quite good. Now we have to wait."
Injured squad or not, Klopp still retains a sense of optimism for the match against their closest rivals saying: "We have the advantage of playing at home. But that's the only benefit. We must take advantage of that."