Philadelphia Flyers defenseman Matt Niskanen has decided to retire from the NHL.

Niskanen, 33, had one year left on his contract at $5.75 million against the salary cap, which will come off the Flyers' books as a result of his retirement.

"Thank you to the Flyers organization for the opportunity to play in Philly last season," Niskanen said in a statement released by the team. "I'd also like to thank the fans for their support and lastly, I wish my teammates the best of luck."

Niskanen did not detail why he decided to hang up the skates.