Willy was scheduled to be re-evaluated by medical staff Friday with what the CFL team is calling an upper-body injury.
Head coach Mike O'Shea will provide an update on Monday and Willy's status for next Friday's game against Montreal is unknown, the Blue Bombers said in a release.
Willy left the game with 20 seconds remaining in the first quarter after taking a helmet-to-helmet hit from Ticats defensive end Adrian Tracy. Hamilton went on to win 52-26.
The 28-year-old quarterback appeared to be knocked out as medical staff looked at him. After a couple minutes on the turf, he walked off the field to the locker-room and was replaced by Brian Brohm.
Willy is the fifth quarterback to be injured in the first two weeks of the CFL season, joining Montreal's Jonathan Crompton and Dan LeFevour, Edmonton's Mike Reilly and Saskatchewan veteran Darian Durant on the sidelines.