Memphis then shipped Calderon to Detroit for Austin Daye and Tayshaun Prince.

The Grizzlies also received a 2013 second-round pick from Toronto as part of the deal.

The Dallas Mavericks, sources said, were also interested in acquiring Calderon but were not prepared to surrender swingman Vince Carter, whom Memphis coveted to help fill the void created by Gay's departure.

Memphis general manager Chris Wallace thanked both Gay and Haddadi for their time with the Grizzlies.

"We are excited to add three players who bring with them a tremendous amount of value to our team and have achieved incredible success on the pro, college and Olympic levels," Wallace said in a statement Wednesday night. "In these players, we welcome NBA Champion and Olympic gold medalist Tayshaun Prince, as well as up-and-coming athletic forwards Ed Davis, who won an NCAA title at North Carolina, and Austin Daye."

The moves surprised many around the league, including Calderon.

"It's been my home for eight years," Calderon said in Atlanta, shortly before leaving the arena. "I've done everything possible for this team. It's tough. The fans have been with me since Day 1. It's tough."

Prince and Daye have both spent their entire careers with Detroit, and Prince was the last link to the proud championship team of 2003-04.

"Trading a player like Tayshaun Prince, who has meant so much to our organization and contributed to our championship success, is never easy," Pistons president Joe Dumars said in a statement. "We want to thank Tayshaun for his professionalism and contributions over the last 10 years. We also appreciate everything that Austin Daye has done for our team both on and off the court over the past three-plus years."

Gay, averaging 17.2 points and 5.9 rebounds, signed a five-year, $82 million maximum contract in July 2010 with Memphis. The 6-foot-8 small forward is due $16.5 million this season with $37 million more over the next two years. That's a big number for new owner Robert Pera, who took over the franchise last November and has quickly started addressing the team's salary situation.

Just more than a week ago, the Grizzlies sent valuable reserve Marreese Speights and two other players to Cleveland in a move that cleared $6.4 million in salary and avoided a $4 million luxury tax hit this season. Team officials said that move put the Grizzlies in position not to have to make a move this season.

Memphis coach Lionel Hollins had been lobbying to keep his five starters together the rest of this season, but he apparently lost that fight. It's a significant move for a team that was fourth in the Western Conference and three games behind the third-place Clippers.

"Wow," Grizzlies point guard Mike Conley tweeted.

Trading away Gay also eases a luxury tax hit due next season, while concentrating the team around center Marc Gasol and All-Star forward Zach Randolph. The Grizzlies had their best playoff run in 2011 when they knocked off then-No. 1 seed San Antonio before losing to Oklahoma City in seven games in the Western semifinals -- all with Gay on the bench after needing season-ending shoulder surgery.

"Wow that was 1 crazy trade today," Oklahoma City center Kendrick Perkins tweeted. "Are you serious Rudy Gay is right there under KD, Lebron, Kobe, and Melo. (hashtag)badtrade."

They do run the risk of upsetting the chemistry on a tight-knit group, even if there were some questions of how Gay's scoring fit in with the ball-dominant frontcourt of Gasol and Randolph.