The Blue Jays placed Guerrero on the 7-day concussion IL on Saturday, Mitch Bannon of The Athletic reports.
Guerrero suffered the concussion after colliding with George Lombard while sliding into third base during Friday's contest. He'll now be forced to sit out until at least Aug. 22, leaving Charles McAdoo and Kazuma Okamoto as the remaining candidates to start at first base for the Blue Jays. Daz Cameron will come up from Triple-A in a corresponding move to round out Toronto's bench depth.