Borussia Dortmund have been left sweating on the fitness of Lukasz Piszczek ahead of Saturday's home game against Rasenballsport Leipzig. The full-back, who has netted four times for the Black and Yellows this season, missed out on training on Thursday.

In his press conference on Friday, Thomas Tuchel cited "muscular problems in the back region" but did not definitively rule the Pole out. "We need to wait and see. He will undergo tests this afternoon," the coach explained.

The approval of new signing Alexander Isak's transfer yesterday makes the Swede "a candidate for inclusion in the squad," according to Tuchel, especially as he has trained well. But the 17-year-old requires caution. "He is still settling in here. There is a lot of competition for places and we need to weigh up what we can expect from him and what we can test out," said Tuchel, who added that there was a "high probability that this match comes a bit too soon for him." It therefore seems as if Isak will experience his first match at Signal Iduna Park from the stands. (br)