The Ottawa Senators traded Fisher to the Predators on Thursday for a first-round draft pick and a future conditional pick.
Underwood lives in Nashville, and the couple married last summer in Georgia. Fisher, 30, has 24 points this season and had been tied for the Senators' lead in goals with 14.
"I'm sure there was a lot of places and a lot of teams that would've coveted Mike," Nashville general manager David Poile said on a conference call Thursday afternoon. "But on the surface the fit for Nashville with his wife, certainly we're hoping is going to be an attractive situation for Mike and his wife."
The Predators hope to have his work visa completed Friday so he can be in the lineup Saturday night against Colorado.
Fisher told SENS TV on the Senators' website that news of the trade was a bit of a shock that he still was trying to process. Going to Nashville made it easier because he said he is excited about being a part of the Predators.
"They're a very good team, and it'll be kind of like going home for me. I'm sure my wife won't be disappointed, either. But I think it's a great place for me and family and everything," Fisher said.
Underwood issued a statement, saying Fisher and she will truly miss Ottawa.
"Mike has been such a big part of the community, and I will never forget how they welcomed me with open arms," she said. "We obviously love Nashville, and the teams' decision for him to now play with the Predators is an exciting opportunity for Mike. I support him wherever he plays!"
Poile said the Predators always have liked Fisher and his game from his scoring to killing penalties and playing on the power play. He averages more ice time per game than any forward on the Predators right now, and Fisher also is under contract for the next two seasons.
"This is not a rental like a lot of deals are at the trading deadline," Poile said in a conference call. "Mike is signed for the next two years so this is a deal that is hopefully going to help us down the stretch this year, but hopefully help us for a lot of years to come."
The teams began talking about this trade a week ago, and this deal is costly for Predators.
The club is sending its first-round pick in the 2011 draft and a conditional pick in 2012 - which would be a third-rounder if the Predators win a playoff series this year. The pick will escalate if the team wins two or more postseason series.
But Nashville is desperate to advance past the opening playoff round after reaching the postseason five times in the past six years, and Poile didn't have to part with any of his highly prized prospects or anyone on his roster to make this deal.
Nashville currently is five points behind first-place Detroit in the Central. Ottawa is last in the Southeast Division with 42 points.
"It's a fine line here in the NHL," Poile said. "We're obviously banking that Mike Fisher, along with the parts we already have, will just kind of complete our forward line and just make us a little bit better."
Fisher, 30, has 28 points in 75 postseason games, which immediately makes him the most experienced in the playoffs on the Predators' roster. He helped Ottawa go past the first round four out of six playoff appearances, including the 2007 Stanley Cup Finals and the 2003 Eastern Conference finals.
The 11-year veteran has 167 goals and 181 assists in 675 regular-season games, all with the Senators. He was a finalist for the Selke Trophy as the NHL's top defensive forward in 2006, and the 6-foot-1, 208-pound forward had career-highs with 53 points and 25 goals and 10 power-play goals last season.
Predators fans should get to see more of Underwood as a result of the trade.
The five-time Grammy Award winner won the fourth season of "American Idol." She has sold more than 13 million albums with 13 No. 1 hits. She is also twice been named the Academy of Country Music Entertainer of the Year, and is a three-time CMA and ACM Female Vocalist winner.