Warsaw - Borussia Dortmund striker has picked up a knee injury while on international duty with Poland.

Lewandowski will play no part in his country's 2014 FIFA World Cup qualifier with San Marino on Tuesday and will now return to Dortmund for treatment.

Not serious

Although the injury is not believed to be serious, Dortmund will only know the full extent of the damage once club doctor Markus Braun has examined the striker.

The Yellow-Blacks are currently top of the Bundesliga table, having won all four of their league matches so far.