Alfaro was placed on the 10-day injured list with right knee inflammation Friday, retroactive to Aug. 25.
Alfaro started two of the last three games and went 0-for-8 with five strikeouts. However, he's apparently dealing with a knee issue that will keep him out for at least a week and a half. A timetable for his return isn't yet clear, but Luis Campusano was recalled to provide additional depth behind the plate.