Campbell was scratched from the lineup ahead of Thursday's game against the Blue Jays due to right rib discomfort, Christopher Smith of MassLive.com reports.
The severity of Campbell's injury remains unknown, but it's apparently enough of a nuisance to warrant a day off Thursday. While we wait for more information, Jarren Duran will shift to center field to cover for the 22-year-old, opening up left field for Rob Refsnyder.