BERLIN (Reuters) - Germany striker Mario Gomez has been ruled out of World Cup qualifiers against the Czech Republic and Northern Ireland this month due to muscle stiffness, his club VfL Wolfsburg said on Tuesday.

Gomez also missed their first qualifier in September after being injured during Euro 2016 in July.

"He called off the trip with the Germany team due to muscle stiffness and will miss training for a few days," Wolfsburg said.

It was not immediately clear if Germany coach Joachim Loew would replace him.

The Germans, who won their Group C opener against Norway 3-0 in September, take on the Czech Republic in Hamburg on Oct. 8 before hosting Northern Ireland in Hanover three days later.

(Reporting by Karolos Grohmann, editing by Ed Osmond)