The 22-year-old Negrin has played in 26 games with the Abbotsford Heat of the American Hockey League this season, collecting one assist and 12 penalty minutes.
The Vancouver, B.C., native has played in three career NHL games with the Flames, collecting one point and two penalty minutes. He was originally drafted by the Flames in the third round, 70th overall, in the 2007 NHL Entry Draft.
Aliu, 22, has four goals and one assist for five points and 12 penalty minutes in 13 games this season with the AHL's Heat while on loan from the Jets.
Drafted by the Chicago Blackhawks in the second round (56th overall) in 2007, he was traded to the Jets, along with Dustin Byfuglien, Ben Eager and Brent Sopel to the Atlanta Thrashers for Marty Reasoner, Jeremy Morin, Joey Crabb, a first and a second round selection in 2010.