In five seasons with the Senators, Zibanejad had 64 goals and 151 points in 281 games. He was selected by Ottawa with the No. 6 pick of the 2011 NHL Draft.
Zibanejad has a $2.625 million NHL salary-cap charge this season, the last of his contract, according to General Fanager. He can become a restricted free agent after the season.
Brassard, 28, has a $5 million salary-cap charge for the next three seasons, meaning the Rangers are saving $2.375 million this season.
"You can say it's cap space if that's the way you want to look at it," Gorton said. "But for us, this is a younger player that is almost six years younger that's coming off two 20-goal seasons that we think is heading to the prime of his career. The ability to get him, to get a younger player, to get a guy that's fast, big (6-foot-2, 222 pounds), plays real well in his own zone, can do a lot of things for us, that's the exciting piece. The fact that we have salary-cap space is good and we'll look at everything now."
Brassard, 28, led the Rangers last season with 27 goals, the most he's scored in an NHL season, and eight power-play goals, and was second with 58 points (Mats Zuccarello, 61). Brassard had four points in five Stanley Cup Playoff games.
"We felt Mika has great potential down the road, but we felt with Derick we were getting someone that was more proven, and a better hockey player at this point in time," Senators GM Pierre Dorion said, according to Pro Hockey Talk. "Our ultimate goal is to make the playoffs again, and we feel Derick's going to help us make the playoffs."