Oliver Kirch and Ji Dong-won sustained thigh injuries in training on Tuesday, with the former in danger of missing half of Borussia Dortmund's group stage campaign.
Borussia Dortmund's preparations for the season have been dealt a blow with the news that defender Oliver Kirch and forward Ji Dong-won will be sidelined for eight and four weeks respectively.
The players suffered thigh injuries in training on Tuesday ahead of Dortmund's Bundesliga opener at home to Bayer 04 Leverkusen this weekend.
It means Kirch − who started the Schwarzgelben's German Super Cup defeat of FC Bayern München a week ago and their domestic cup tie against SV Stuttgarter Kickers last Saturday − could miss the first three matchdays of the UEFA Champions League group stage, starting on 16/17 September.
Things are not as bad for South Korean international Ji. The 23-year-old, a free transfer from Sunderland AFC this summer, could return for Dortmund's first European fixture of the campaign.