Two months after leading the Nashville Predators to the brink of their first Stanley Cup championship, Mike Fisher, the team's longtime captain, is hanging up the skates, ending a playing career that spanned two teams and 17 seasons.

Announcing his farewell in a thank-you letter published in the Tennessean, the 37-year-old center called retiring "the hardest decision I've ever had to make" but backed up his departure by also calling it the "right" decision.

With Fisher saying goodbye not only to a Predators team to which he became so very attached but also hockey itself, here are three things to know:

The NHL is losing one of its top veteran free agents

If he changed his mind right now about closing his 1,088-game career, he would still be a top-10 unsigned vet. Everyone knew the 2016-17 season could be Fisher's last, so his step out of the spotlight isn't surprising, nor was his free-agent stock ever supremely high. But even at 37, the 1998 second-round draft pick (Ottawa Senators) could've offered someone mid-tier center depth after scoring 18 goals and logging 24 assists, his highest mark in four years, this past season.

Mike Fisher is hanging up the skates after 17 NHL seasons. USATSI

Nashville has two spots to fill

With Fisher out of the picture officially, the Predators are tasked with replacing two roles -- the veteran's position as a captain and his reserve contributions at center. The latter has arguably already been satisfied thanks to the team's addition of Nick Bonino from the Pittsburgh Penguins, not to mention the recently re-signed Ryan Johansen. But the captain slot remains vacant for the time being. The Tennessean thinks defenseman Roman Josi and Ryan Ellis are the top candidates to take it.

Other aging veterans might follow suit

If Fisher's retirement did one thing for fellow aging free agents, it might have been a reminder that it's OK to call it quits. Whereas a guy like Jaromir Jagr has reason to hold out for a 2017-18 opportunity, there are plenty of grizzled vets like Fisher who, for their sake and the sake of any team that banks too much on nostalgia late in the summer, might be best served walking away, at least from the NHL. Only time will tell, but who's to say Fisher's announcement won't serve as the first domino in a line of other farewells?