Bayer Leverkusen forward Javier Hernandez has been ruled out of the club's Europa League round of 32 tie against Sporting Lisbon.
Hernandez scored Leverkusen's only goal in their 3-1 defeat to Werder Bremen in the DFB-Pokal on Tuesday, but went off injured just before the hour mark.
The Mexico international sustained a minor torn muscle fibre in his left gluteal muscle, and is expected to be out for the rest of February.
"We will most likely be without him for the next two weeks," Leverkusen coach Roger Schmidt said.
"The injury is a bit unusual, and we can't really foresee when he'll be fit again. The healing process can take one, two or three weeks."
Along with Leverkusen's Europa League tie with Sporting, Hernandez is also set to miss Bundesliga fixtures against Darmstadt and Borussia Dortmund.
"In Stefan Kiessling and Hernandez we have two real attackers in our squad. We need to play differently in attack at Darmstadt," Schmidt added.
"The key to success will again be courageous defending, and independently from Hernandez's absence we need be more dangerous in front of the goal as a team, also the midfielders."
Leverkusen are sixth in the league table, three points off third-place Hertha Berlin.