Mariusz Fyrstenberg

Mariusz Stanisław Fyrstenberg (born 8 July 1980) is a retired Polish tennis player who was a doubles specialist.

Fyrstenberg primarily partnered Marcin Matkowski. The pair won the Madrid Open twice, in addition to reaching the final at the US Open. They also reached the final of the ATP Finals and participated six times at the event overall.

He is currently the coach of Wesley Koolhof, Jan Zielinski and Hugo Nys.