The 26-year-old was scratched from a spring start on Thursday after bumping his head against some bats in his locker, Davidi previously reported.
Pompey - who was competing for an Opening Day spot in Toronto's outfield to begin 2019 - has a history of concussions.
In 2016, Pompey suffered a concussion after crashing into a wall while trying to catch a fly ball. He suffered another one in 2017 sliding into second base while playing for Canada at the World Baseball Classic.
The outfielder had a good shot of making the team, as he's out of minor-league options.
Toronto is expected to enter the year with Billy McKinney, Randal Grichuk, and Kevin Pillar as the team's starting outfield, and will likely find a spot for Teoscar Hernandez, who's having an incredible spring (.410/.489/.590 with two home runs and eight RBIs).
Pompey, a native of Mississauga, Ontario, has only appeared in 64 games for the Blue Jays since making his major-league debut in 2014, hitting .221/.289/.372 with three home runs, 10 RBIs, and eight steals.