Patrick Helmes has been ruled out for two to three weeks after suffering a calf injury during Bayer 04 Leverkusen's 3-0 victory over SC Tavriya Simferopol on Thursday.

The 26-year-old forward was withdrawn midway through the second half of the UEFA Europa League play-off first leg after tearing muscle fibres. He will miss next week's return trip to Ukraine and is also a major doubt for Germany's opening UEFA EURO 2012 qualifiers against Belgium and Azerbaijan at the beginning of September.

"The season has not even started properly and we have three injured players," said Leverkusen coach Jupp Heynckes, already having to contend with the absences of Lars Bender (calf) and Sidney Sam (back). "It is especially annoying with Patrick, because he had a great pre-season and was looking really good. The timing is most unfortunate."