Once he went to Washington, and the Capitals were ready to trade the Czech forward, Phoenix jumped on the chance.
The Coyotes added what they hope will be a valuable scorer, acquiring Erat and forward John Mitchell from the Capitals for forward Chris Brown, defenceman Rostislav Klesla and a fourth-round selection in the 2015 draft on Tuesday.
"We like Martin, we like what he can add," Coyotes general manager Don Maloney said. "We think he will fit our style, very similar to Nashville's, he will excel.
Erat had some good offensive seasons with the Predators, scoring at least 49 points eight times. The 32-year-old forward didn't have the same production in Washington, registering two goals and 25 assists since being traded to the Capitals during the 2012-13 season.
The Coyotes hope he will have a resurgence, possibly as the missing piece on Phoenix's second line with fellow Czechs Martin Hanzal and Radim Vrbata.
"We're going to look at it," Maloney said. "But more than anything, I think he needed a breath of fresh air. He's excited to come here, as much to get out of the snow and ice as much as anything else."
The NHL trade deadline is Wednesday, and Maloney said the Coyotes could pull off another deal or two, possibly to get another scorer.
Brown and Klesla will report to Hershey of the American Hockey League.