A native of Zielona Góra, Nijaki played Davis Cup for Poland and was a two-time national singles champion.

Nijaki made his Davis Cup debut in a 2000 tie against Estonia and partnered with Marcin Matkowski to win the doubles rubber.

In 2002 he featured in the main draw of an ATP Tour tournament in Sopot, the Idea Prokom Open, where he had to retire hurt during his first round match against Paul-Henri Mathieu with an elbow injury.

[2] Outside of professional tennis he also played at collegiate level in the United States for Texas Tech University.

[3] He was initially with Texas Tech in 2002, before leaving to turn professional, but returned in 2005 and in his sophomore season was named Big 12 Newcomer of the Year.