The 34-year-old, who amassed more than $7 million in prize money before quitting the tennis tour at the end of last season, is switching to the more obscure sport of floorball -- a six-a-side indoor variant of field hockey played with a lightweight ball.
"I like challenges and putting myself on the line," Finland's most successful tennis player said on Monday, announcing he was joining Tampere Classic of the Finnish Floorball League.
"I don't assume or take success in the league for granted, but I also don't set any boundaries for myself."
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Floorball was developed in Sweden in the 1960s and is most popular in the Nordic countries. According to the International Floorball Federation, the sport has around 300,000 licensed players worldwide.
Once ranked in the world's top-15 tennis players, Nieminen recorded victories over big names including Andre Agassi and Novak Djokovic during a career in which he became the first Finn to win an ATP singles title.
(Reporting by Tuomas Forsell, Editing by Ed Osmond)
