Now he is with a new team -- playing a new position. Well, it's not that new.
Byfuglien heads into this season adjusting to life with the Atlanta Thrashers and back to his original position on defense. The Thrashers hope he thrives in coach Craig Ramsey's go-go system.
"I enjoy defense more than I enjoy forward," said the 6-foot-5, 265-pound Byfuglien.
The Thrashers obtained the 25-year-old Byfuglien and three other Blackhawks in a pair of deals.
Byfuglien said that he couldn't be happier with the change, although on the surface it's somewhat baffling after the way he had used his speed and size so well at forward. He scored five game-winning goals during the Blackhawks' run to the Stanley Cup, although he did play some defense for the Blackhawks last season, as well.
Thrashers general manager Rick Dudley talked to Byfuglien about the potential return to defense as soon as the trade was made and Ramsey, who wants his defenseman to contribute to the offense by joining the rush, signed off on the switch before the start of training camp.
"We'd like to see Buff play defense," Ramsey said. "We think he can do it. I think he can bring something to the table."
The Thrashers open the season on Friday against Washington and Byfuglien played in just two of the six preseason games because of a tender ankle. But he says the return to his old position hasn't been a difficult transition despite the shortage of game action.
"So far, so good," Byfuglien said after Monday's practice.
The Thrashers made the switch despite not having a proven go-to goal scorer after the trade of Ilya Kovalchuk to New Jersey at the deadline last season. But Ramsey, who took over for John Anderson as coach, believes in giving four lines substantial minutes and generating offense from his blue line as well as his forwards.
"I want to establish myself as a defenseman," Byfuglien said. "That's what I always played coming up. I think I did a good job at forward in Chicago, but I think I can be the player on defense that I was at forward. I'd like to add that tool to my bag. I think I'll fit in here very well on defense."
Ramsey said Byfuglien's enthusiasm has been wonderful.
"He's got a ways to go, but he's a big body back there with a good stick, which is really a nice thing to have," Ramsey said. "And he can jump up from there [to join the rush], which makes him hard to cover."
Thrashers winger Ben Eager says his former Chicago teammate is a difficult matchup wherever he is on the ice.
"He's tough to play against no matter where he's at," Eager said. "He skates really well for a big guy. When he gets going, he's a handful to stop out there."
The Thrashers were 0-5-1 in the preseason as the old and the new players tried to get used to Ramsey's system.
"We're still learning everything. It takes a while to get the old stuff out of your head," Byfuglien said. "But it's going to be fun. It's a good system."
The Thrashers have reached the playoffs just once in their history and have never won a postseason game. But Byfuglien, who played three seasons in Chicago, likens his new team to where the Blackhawks were just a few years ago.
"I think there is a big upside here," he said. "We've got a lot of young, hard-working players and some veterans who know how to win. I see a lot of good things. I think it's going to be exciting."