Fermin was removed from Thursday's game against the Dodgers in the fifth inning after taking a foul tip off the mask, Jeff Sanders of The San Diego Union-Tribune reports.
Fermin spent time on the 7-day IL last month after he was concussed when a warmup pitch struck him in his mask. Prior to exiting Thursday, Fermin went 1-for-2 with a double. Rodolfo Duran replaced him at catcher.