BERLIN, Aug. 16 (Xinhua) -- Schalke will be without their defender Matija Nastasic due to a ruptured Achilles tendon, the "Royal Blues" confirmed in an official statement via the club's official homepage on Sunday.

The 22-year-old defender ruptured his Achilles tendon following a challenge with Bremen's Levin Oeztunali in the 13th minute. Nastasic had to be replaced by Roman Neustaedter before he underwent a surgery the same day.

The Serbian international will be thus out of action for a few months. The "Royal Blues" encounter newly promoted Darmstadt for the second round in Bundesliga on Saturday.