Peter Bosz rued Borussia Dortmund's bad luck as further injuries left his defence down to the bare bones for the Bundesliga clash with RB Leipzig.

Dortmund top the table ahead of welcoming last season's runners-up Leipzig to Signal Iduna Park, but Bosz has been dealt a blow by further defensive knocks in the international break.

Lukasz Piszczek has joined captain Marcel Schmelzer (ankle), Erik Durm (hip) and Raphael Guerreiro (ankle) in the treatment room after injuring his right knee in action for Poland, leaving Bosz frustrated.

"We have problems in the full-back position," he told a pre-match news conference. "Piszczek unfortunately does not look good. We will miss him in the coming months.

"It is unbelievable. The full-backs are always hurt. This is not easy. A system change is possible. We no longer have lots of options, but we will have to choose."

Centre-back Sokratis is also a doubt, having just returned from international duty with Greece, although Bosz is hopeful he will be fighting fit come Saturday's game.

"He only partially trained [on Thursday]," the coach said of Sokratis. "I hope that he is fully involved [on Friday] - only then is he an option."

Bosz also admitted he has had to lift star men Pierre-Emerick Aubameyang and Christian Pulisic after their respective countries - Gabon and the United States - missed out on World Cup qualification.

"Yes, [Aubameyang is hurting] and you can imagine the same with Pulisic," he said. "It is always difficult. On the other hand, we must go on. We've talked about it."