Poland travel to the Amsterdam Arena on Friday 4th September (7:45pm) to face the Netherlands, before they play host to their clash with Bosnia and Herzegovina on Monday 7th September (7:45pm).
Klich was a key member of the Poland side which won 8 of their 10 games, topping their group and qualifying for the EURO 2020 championships.
The midfielder also featured an incredible 47 times for Leeds last season, scoring 7 times, as the Whites returned to the Premier League after 16 years.
Alongside Bosnia and Herzegovina and the Netherlands, Poland will also face competition from Italy in Group A1.