The Coyotes acquired the center and right wing B.J. Crombeen from the Tampa Bay Lightning for a sixth-round pick in the 2015 NHL Draft. Tampa Bay earlier obtained Gagner from the Edmonton Oilers in a trade for right wing Teddy Purcell.
"It's been a roller coaster of emotions," Gagner said, according to The Canadian Press. "I was talking to my agent, and he had said when Tampa [Bay] traded for me that there might be something else going on. So it was something that I was prepared for. I wasn't really expecting to be traded (again) today."
LIGHTNING WHEELIN' AND DEALIN'
The Coyotes were in the market for a center after buying out Mike Ribeiro on Friday.
"It came together in a hurry," Arizona general manager Don Maloney said, according to the CP. "I think there's three [teams] that feel pretty good about our day so far."
Gagner, 24, had 10 goals and 27 assists in 67 games last season after missing the first 13 games recovering from a broken jaw. He has two years remaining on a contract with an annual NHL salary-cap charge of $4.8 million, according to CapGeek.com.
Gagner was the No. 6 pick in the 2007 NHL Draft and had eight points (four goals, four assists) in a game Feb. 2, 2012 against the Chicago Blackhawks.
"[Sam] has the intelligence, character and skill set we were looking for and we believe he has further growth in his game," Maloney said in a statement.
Crombeen, 28, had three goals and seven assists in 55 games last season. He had 79 penalty minutes and has 771 in 387 NHL games. He will make $1.15 million this season before becoming an unrestricted free agent, CapGeek states.
"B.J. is a great fit for us," Maloney said. "He is a big, strong, character player who will be a leader on the ice and in our locker room."
Purcell, 28, had 12 goals and 30 assists in 82 games last season. The undrafted free agent has missed three games in the past four seasons and has two years remaining on a contract with an annual NHL salary-cap charge of $4.5 million, according to the website.
Thompson, 29, had nine goals and seven assists in 81 games. He will make $1.6 million in each of the next three seasons, according to CapGeek.