The BVB defender injured himself when conceding a penalty in the defeat to Hoffenheim on Saturday and there is a chance that he may now miss out on the trip to Wembley
The centre-back injured himself when conceding a penalty prior to die Hoffe's 76th-minute equaliser at Signal Iduna Park, as he came off worse for wear from a collision with Kevin Volland before being replaced by Felipe Santana.
"We are worried about Hummels because of the Champions League final coming up," the BVB coach told Sky Sports after full-time. "We just have to wait. There is a chance but it will be tight.
"His ankle is swollen. It will be close [whether he plays] at Wembley. But our club doctor says there is a chance."
Dortmund general manager Michael Zorc believes that Hummels' injury could be serious but is hopeful that a medical examination later this weekend will reveal he can play on May 25.
"There is hope for Wembley," he told Reviersport. "But a ligament has been damaged. On Sunday there will be further tests."
The Schwarzgelben will also be hoping that Mario Gotze can continue his positive steps towards full fitness as he joined in light training this week ahead of the showpiece event at Wembley.
Both players are hugely influential to BVB and their supporters will be keen to see them recover fitness in time for the European cup final against pre-match favourites and runaway Bundesliga champions Bayern Munich.