Borussia Dortmund is waiting on the fitness of defensive chief Mats Hummels for Tuesday's Bundesliga top-of-the-table showdown at home to leaders Bayern Munich.
The 2014 World Cup winner aggravated his Achilles tendon in Saturday's 2-0 win at Wolfsburg which kept second-placed Dortmund four points behind leaders Bayern, who are chasing an eighth straight league title.
Hummels came off at half-time on Saturday, but Dortmund still hope he can lead the hosts' defence against his former club Bayern.
"Mats has a problem with his Achilles tendon and we hope he can play on Tuesday," said Dortmund sports director Michael Zorc.
"He has had the problem for a while."