Plawecki was removed from Sunday's game against the Royals with left hamstring tightness, Christopher Smith of The Springfield Republican reports.
The 30-year-old went 0-for-1 before being replaced by a pinch hitter during the fourth inning. The severity of the injury remains unclear, but Plawecki could be headed for the injured list if he's forced to miss more than a day or two, since the Red Sox are unlikely to play for long without a viable backup to starting catcher Christian Vazquez.