National Hockey League roundup

"This is the hardest decision I've ever had to make, but I know I've made the right one," the 37-year-old Fisher wrote in a letter published in The Tennessean on Thursday. "I've decided to retire from the NHL."

Fisher, who is married to country music star Carrie Underwood, recorded 18 goals and 24 assists in 72 games last season. He added four assists in 20 postseason contests to guide the Predators to the Stanley Cup Final, where they lost to the defending champion Pittsburgh Penguins.

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Arizona Coyotes defenseman Jakob Chychrun had surgery to repair a knee injury that he suffered this week during offseason training.

Chychrun is expected to make a full recovery, according to the Coyotes, but will be out indefinitely. The team said it would provide an update at the start of training camp in mid-September.

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The Calgary Flames announced several front office moves, the most significant of which was the promotion of Don Maloney to vice president of hockey operations.

Maloney joined the Flames last year as a scout after serving as the Arizona Coyotes general manager from 2007 to 2016.

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The Florida Panthers reached agreement with defenseman MacKenzie Weegar on a one-year, two-way contract, the team announced.

Weegar, 23, did not record a point while appearing in three games with the Panthers during the 2016-17 season. He made his NHL debut with Florida on April 3 against the Montreal Canadiens.