Demski, six-foot 215 pounds, was selected by Saskatchewan sixth overall in the 2015 CFL Draft, after playing four seasons with the University of Manitoba.
The 21-year-old Winnipeg native made 27 catches for 589 yards and five touchdowns while also rushing for 47 yards on six carries in 2014. He also contributed on special teams with 19 punt returns for 272 yards and a touchdown for the Bisons.
Demski was named a 2014 CIS second-team All-Canadian and a Canada West all star.
Details of the contract were not released.