The Red Sox designated Alfaro for assignment Tuesday, Ian Browne of MLB.com reports.
Alfaro spent just under a month on the Red Sox's 40-man roster and 26-man active roster, serving as the No. 2 option at catcher while Reese McGuire (oblique) was on the shelf. As anticipated, Alfaro finds himself as the odd man out with McGuire returning from the IL on Tuesday to reclaim his role as Connor Wong's top backup. Alfaro saw limited work behind Wong while he was with Boston, going 2-for-17 with two walks against three strikeouts. The 30-year-old will now be exposed to waivers and could hold some appeal for an organization looking to upgrade its catching depth.