Monasterio went 1-for-3 with a walk and a double in Monday's 4-2 win over the Athletics.
Monasterio started a fifth consecutive game at shortstop and extended a hit streak to nine contests, during which he's 12-for-26 (.462) with six walks, six doubles, one triple, one home run, five RBI and five runs scored. Even before the Red Sox optioned Tsung-Che Cheng back to the minors over the weekend, Monasterio had taken hold of the shortstop spot. It should be his until Trevor Story (sports hernia) is ready to return at some point in August.