The Hamilton Tiger-Cats will be without their big off-season acquisition for at least their next game.
Head coach Kent Austin said quarterback Zach Collaros won't play against the Calgary Stampeders on Friday after the 25-year-old suffered a head injury in Hamilton's 28-24 loss against the Edmonton Eskimos on July 4.
Austin did not call the injury to Collaros a concussion and has no timetable for his return. He also said he expects to use Jeremiah Masoli and Dan LeFevour in their game against Calgary, but didn't name a starter.
Collaros was injured midway through the second quarter when defensive end Odell Willis smashed into the quarterback's facemask with his own helmet. Collaros lay motionless for a short while before leaving under his own power.
Hamilton signed Collaros during the off-season after the Toronto Argonauts released the Cincinnati product.
Ticats receiver Andy Fantuz participated in his first full practice since suffering a concussion in the pre-season and Austin is hopeful he'll play against the Stampeders if he doesn't suffer setbacks.
Hamilton also signed international quarterback Jacory Harris and international offensive lineman Jeremy Lewis on Sunday.
The Ticats are 0-2 on the season.