SV Werder Bremen leading goalscorer Claudio Pizarro has been ruled out of Saturday's trip to Dortmund because of injury.
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The 37-year-old is still feeling the after-effects of a back strain picked up in Peru's 1-0 defeat to Uruguay in the CONMEBOL section of 2018 FIFA World Cup qualifying on Tuesday.
The news will come as a real blow to Werder head coach Viktor Skripnik, Pizarro having scored six goals in his last four Bundesliga matches and 12 for the season.
The Green-Whites travel to Dortmund in 14th place, with just a point separating them from the relegation zone.