The 26-year-old Comrie is earning US$3 million this season and will be an unrestricted free agent July 1. He has 20 points (7-13) in 24 games with the Coyotes this season.
"We have been working on this for a long time," Senators GM John Muckler said Wednesday at a news conference. "This was the best guy available at the time. We have been talking to our scouts about this for some time."
With top two centres Jason Spezza and Mike Fisher out with knee injuries, Muckler has been working the phones in the past two weeks trying to find some help. He also tried to acquire Petr Nedved off re-entry waivers from the Philadelphia Flyers but the Edmonton Oilers beat him to the punch Tuesday.
So Muckler pulled the trigger on Comrie and it cost a 23-year-old centre in Kaigorodov, who left the Senators for Russia earlier this season after refusing an AHL assignment. The Senators subsequently suspended him.
The Coyotes already have a suspended Russian forward of their own in Enver Lisin, who failed to report to Phoenix's AHL affiliate in late November and went home to Russia.
The Coyotes had a surplus at centre after the return of Steve Reinprecht this week added to a group that already included Comrie, Yanic Perreault, Dave Scatchard, Mike Zigomanis, Patrick Fischer, Jeremy Roenick, Mike Ricci and Joel Perrault. Comrie also didn't fit into their future plans.
The Senators were seen by many as needing a centre even before the injuries to Spezza and Fisher. Also sidelined is centre Antoine Vermette, who remains day-to-day with a hip injury.
"Very seldom are you going to lose your (top three) centre-ice men," said Muckler. "We felt we needed a little more offence. The team has been playing very well. We just felt over the long run we needed a push on the offensive side."
Once everyone is healthy Comrie will likely be the No. 2 centre.
"He should add some offence to this group," said Senators coach Bryan Murray. "With the injuries the way they are, he's going to add something here. There's an offensive role for a player of this nature and (he) gives us strength down the middle."
In six NHL seasons, Comrie has 110 goals and 127 assists 345 career games with Edmonton, Philadelphia and Phoenix. The Edmonton native was drafted by the Oilers in the third round, 91st overall, of the 1999 NHL entry draft.
He had a career-high 60 points (33-27) in 2001-02 with the Oilers as well as last season with the Coyotes (30-30).
Murray remembers Comrie's days as an Oilers when Murray was the GM in Anaheim.
"He seemed to be a thorn in the side of our team every time we would go in there," Murray said. "He's a skilled player, a point-getter. He's played pretty well in the NHL. He should add some offence to this group. We've been short in our ability to score. Mike gives us an upgrade."