Borussia Dortmund are making a bright start to the season but are doing so against a backdrop of mounting injury problems that will test the depth of their rebuilt squad. A 3-2 win at Hoffenheim on Saturday kept them second in the Bundesliga with six points from two games, yet the match brought fresh concern when defender Filippo Mane was forced off with a right thigh injury after half an hour. His absence would be a real blow. The 21-year-old had been one of the standout performers in pre-season under Niko Kovac and was pushing hard for a regular starting spot in the back three.

The injury list was already significant before Mane went down. Captain Emre Can and centre-back Nico Schlotterbeck remain in individual training following serious knee injuries, and summer signing Giannis Konstantelias is facing months on the sidelines after tearing his cruciate ligament on his Bundesliga debut against Hamburg. That blow forced the club to act quickly in the final days of the transfer window, bringing in Arsenal's Ethan Nwaneri on a season-long loan. The 19-year-old made his debut off the bench at Hoffenheim, and his arrival gives Kovac a creative option in the forward line. However, transfer expert Fabrizio Romano has reported that Arsenal inserted a clause allowing them to recall Nwaneri as early as January, a scenario that carries uncomfortable echoes of the Aaron Anselmino situation last season.

Off the pitch, the club's financial picture is improving. According to Sport Bild, Dortmund are owed around 120 million euros in outstanding transfer payments from previous sales. The Champions League campaign opens on Tuesday at Signal Iduna Park against Villarreal, a fixture that carries both sporting and financial weight as the club targets at least the last 16.