Robert Lewandowski says he has endured "many sleepless nights" after Poland's disappointing World Cup and that his poor performance is still affecting him.
The striker failed to score in Russia this summer as Poland made a premature exit in the opening stage despite being the seeded team in Group H.
And Lewandowski told Przeglad Sportowy that it has not been easy to put his failure behind him
"I had many sleepless nights. I was thinking about what went wrong and several times coming back...