Barcelona's injury troubles in the final third continued after Robert Lewandowski picked up a hamstring injury while on international duty with Poland. 

Lewandowski scored in Poland's 2-0 win over Lithuania on Sunday, leaving them second in Group G of their World Cup qualifying campaign with two games remaining. 

However, the 37-year-old's performance, which saw him net his 87th goal for his country, has come at a cost for Barcelona, who are second in LaLiga. 

Lewandowski will therefore miss this weekend's league clash with Girona at Estadi Olimpic Lluis Companys, though the Blaugrana did not put a timeframe on his return to action. 

After their match against Girona, Barcelona face Olympiakos in the Champions League before the first Clasico of the season away to Real Madrid on October 26. 

"Robert Lewandowski has suffered a hamstring injury in his left thigh," Barcelona said in a statement on Tuesday.

"He will be sidelined, and his recovery time will depend on how the injury progresses."

Lewandowski has scored four goals in nine appearances in all competitions this season, a total only bettered by Ferran Torres (10), who is also sidelined with injury. 

The likes of Raphinha, Gavi, Dani Olmo, Marc-Andre ter Stegen and Joan Garcia are also out with different injury problems. 

However, Lamine Yamal and Fermin Lopez have returned to training and could feature for Flick's team from the bench this weekend.