Caddy was tipped to be one of the big improvers this season after a standout pre-season.
"It was an unfortunate situation where Josh changed direction and heard a crack in his foot," Geelong's general manager Neil Balme said.
"Scans confirmed the injury and we expect him to miss around eight weeks."
In better news for the club, Steven Motlop is set to play in the VFL on the weekend.
Motlop had knee surgery in the off-season, but is likely to find his feet in the reserves before getting back into the seniors.