Rosario, 22, was acquired from the Padres in 2020 alongside infield prospect Hudson Potts in the trade that sent Mitch Moreland to San Diego. Both Rosario and Potts have now been designated for assignment on consecutive days, though, as Potts lost his 40-man spot yesterday when Boston claimed righty Kyle Tyler off waivers from the Angels.
The fleet-footed Rosario has yet to make his big league debut or even reach the Triple-A level. He spent the 2021 campaign with the Sox’ Double-A affiliate, where he posted a .232/.335/.307 batting line with three home runs, 15 doubles, a triple and a strong 12.3% walk rate against a troubling 27.9% strikeout rate. Scouting reports tout his speed, glovework in center and ability to draw walks, but Rosario is lacking in power and has notable concerns about his hit tool. He’ll be traded or placed on outright waivers within the next week.