The Sharks paid a steep price to acquire the 26-year-old Burns, who is eligible to become an unrestricted free agent after next season.
"There's such a shortage of high-end defencemen in this league," general manager Doug Wilson said. "That's why you better move quickly because other people are lined up and involved. There's just not enough good defencemen and centermen around in this league. When they do become available, if you hesitate you don't get them."
They sent a former 30-goal scorer who hasn't even reached his prime in the 24-year-old Setoguchi, last year's first-round pick Charlie Coyle and the 28th overall pick in this year's draft for Burns and a 2012 second-round selection.
After losing in the conference finals the past two seasons, the Sharks hope the addition of Burns helps them get past that hurdle for the first time in franchise history.
"We're right in, we think, our wheel house, our window with our team," Wilson said. "Bringing in a guy with his age and his type of game, it complements where our team is at."
Burns had 17 goals last season, third among all blue liners. He also had 29 assists, giving the Sharks another proven puck-moving defenceman to go along with veteran all-star Dan Boyle.
San Jose's lack of depth on the blue-line was evident in the conference loss to Vancouver, providing an impetus for this move.
"When you don't win you make changes. It happens," coach Todd McLellan said. "Even the Bruins will make changes this year. That's the way the business is set up. For the past few years we felt that we were maybe not as strong on the blue line as we needed to be."
McLellan coached Burns in the AHL during the 2004-05 season, when he made the transition from forward to defence. McLellan gave a glowing review of Burns to Wilson and said he believes he will be one of the top defencemen in the league for years to come.
"He has some offensive instincts that forwards would have driving the puck to the net, protecting it and taking it to the post because he's played up there before," McLellan said. "And he's very good on the blue line. He's a hybrid."
Burns has played 453 career games since joining the Wild as an 18-year-old first-round pick. He has 55 goals and 128 assists in his career, but has not played in the post-season the past three years.
Now he joins a team that has been one of the best in the league the past few seasons.
"To not make the playoffs, it's really hard to look back at your year and feel good about it," Burns said. "To get a chance to play with a great team like San Jose is pretty amazing. I can't wait to get there."
Burns, the Wild's first pick in 2003, was probably their most tradable asset. The Wild have missed the playoffs for three straight years, and general manager Chuck Fletcher spoke of the need to "aggressively" add young players to keep up with the rest of the league.
"We weren't looking to trade Brent Burns, but it came together quickly and in the course of discussing things with Doug Wilson, the pieces came together," Fletcher said after the draft in Minnesota.
Fletcher lauded the addition of Setoguchi, but also was very high on Coyle, who played this past season at Boston University.
"We feel he's one of the top young power forwards in the game," Fletcher said. "We gave up a very important piece in Brent Burns, but our timeframe needs to be stretched back a bit and we need to add more young players. We very quickly assembled a lot of young talent."
Setoguchi got dealt a day after signing a US$9-million, three-year contract. He said after reaching that deal that he couldn't be happier, calling San Jose the best place to play in the NHL.
It will no longer be his home in a move that he said took him be surprise.
"It's tough to leave there," Setoguchi said. "I've been there so long and know so many people there. I've grown to love the city and the organization. That will be tough. But you can't expect to be there forever. Now you have to make new friends and start all over."
Setoguchi overcame a lacklustre start last season before finishing with 22 goals and 19 assists in the regular season. He added seven goals and three assists in the playoffs, including overtime goals to beat Los Angeles and Detroit in the first two rounds. He provides a needed scoring threat for the Wild, whose 203 goals were the fifth fewest in the regular season.
Setoguchi has 84 goals in four seasons in the NHL, including a career-high 31 two years ago. He also has 75 assists in 267 games and has one of the best shots on the Sharks.
The Wild used the pick acquired in the deal to draft centre Zack Phillips from Saint John's of the Quebec Major Junior Hockey League.
AP Sports Writer Dave Campbell in St. Paul, Minn., contributed to this report.