Borussia Dortmund have been dealt an injury blow ahead of the 2025-26 season after confirming defender Niklas Sule has sustained a calf muscle injury.

Sule suffered the issue in Dortmund's 2-1 defeat to Juventus in a pre-season friendly on Sunday at the Westfalenstadion. 

The German defender replaced Mats Hummels in the 19th minute but did not return for the second half of the contest. 

It is believed that the 29-year-old is set to be sidelined for around two months. 

Sule made 21 appearances in all competitions for Dortmund last season as Niko Kovac guided them to a fourth-placed finish in the Bundesliga. 

Indeed, among Dortmund's defenders in 2024-25, only Ramy Bensebaini (109), Nico Schlotterbeck (117) and Waldemar Anton (137) made more clearances than Sule (56). 

Dortmund begin their domestic campaign next Monday when they take on third-tier side Rot-Weiss Essen in the first round of the DFB-Pokal. 

They kickstart their Bundesliga campaign on August 23 against St. Pauli.