It's official. Early Thursday morning, the Chicago Blackhawks traded playoff hero Dustin Byfuglien to Atlanta as part of a multi-player deal.

The Hawks will send Byfuglien, center Ben Eager, defenseman Brent Sopel and prospect Akim Aliu, a second-round pick in 2007, to the Thrashers for the first-round pick (No. 24) Atlanta acquired from New Jersey in the Ilya Kovalchuk trade, a second-round pick (No. 54) that also came from New Jersey, prospect Jeremy Morin, veteran forward Marty Reasoner and winger Joseph Crabb, who played his first 29 NHL games as part of the Atlanta franchise this past season.

"He's a special player," Hawks GM Stan Bowman said during a conference call early Thursday morning. "There's a few different ways you can make up for the loss of him. He's a great player and we're certainly going to miss him. I don't think there's one guy who can replicate what Buff did."

The Hawks and Thrashers have a connection -- Rick Dudley, the Thrashers' new general manager, worked for the Blackhawks for five years before joining Atlanta last summer and being promoted to GM this spring.

Byfuglien, a 25-year-old forward, had 17 goals and 17 assists in 82 games with the Hawks during the regular season, then added 11 goals – including five game-winners, during Chicago’s run to the Stanley Cup. Sopel, 33, had 1 goal and 7 assists in 73 regular-season games and was 1-5-6 in 22 playoff games. Eager had 7 goals and 9 assists with 120 PIM in 60 regular-season games. He played 18 playoff games with 1 goal, 2 assists and 20 PIM.

"It is what it is," Byfuglien said on "The Afternoon Saloon" on ESPN 1000 in Chicago. "It's part of the job. You're not going to stick in one spot the whole time, so I've got to go."

"What we saw in the playoffs is the Dustin Byfuglien I imagined and who could become one of the league's elite power forwards," said Dudley in a 1 a.m. ET press conference call Thursday morning. "He has soft hands and he is as big a player as there is in the NHL. That combination is attractive."

Dudley called Eager "one of the NHL's better forecheckers" and said he adds toughness as both a player not afraid to fight when needed and "hits with a purpose."

Dudley said the deal was in the works for a while, especially after Chicago's Jonathan Toews earned a significant bonus for winning the Conn Smythe MVP earlier this month.

"I think I talked to Stan (Bowman, Chicago GM) more than when we worked together," said Dudley. "I am talking like maybe 50 calls in the last few days."

With the Hawks facing salary cap issues for 2010-11, defenseman Duncan Keith said losing some members of the team that won Chicago's first Stanley Cup since 1961 was inevitable.

"I've kind of heard about it. To be honest with you, it kind of saddens me," he said after winning the Norris Trophy as the NHL's top defenseman at the NHL Awards Show in Las Vegas. "It really does sadden me. Those are my good buddies leaving our team. Benny and Buff, I was with Buff since he was drafted.

"You know things are going to change when you win the Cup the way our Cap situation was, and things have to be made. It's too bad it had to be like this, but at the same time we've got to start looking forward. When these things do happen, I'm sure there might be some more, and it's not going to be fun. We're just going to have to keep moving forward, and a lot of times that's part of the business. It's hockey. Teams change every year and you lose friends, you lose teammates. You stay in touch, but it's not really the same as playing with them."

Reasoner, a 33-year-old who's played 11 NHL seasons, had 4 goals and 13 assists in 80 regular-season games. Crabb had 4 goals and 5 assists in his 29 games. Morin was taken in the second round (No. 45) by the Thrashers last year. He had 47 goals and 36 assists for Kitchener of the Ontario Hockey League in 2009-10, and also scored 2 goals and 5 assists for Team USA’s gold medal-winning squad at the World Junior Championship.

"You can't beat going to a team that just won the Stanley Cup," Reasoner told the Atlanta Journal-Constitution's website.

"It's always a little shocking to be traded, but we've all gone through it before," he said of being traded. "I would have liked to stay in Atlanta for another year and help that team build, but it's a new chapter. It will be exciting. You can tell from watching the playoffs that the Blackhawks have taken over the city."