Basallo tweaked his pectoral muscle during his plate appearance in the ninth inning of Saturday's 6-5 win over the Blue Jays, Jacob Calvin Meyer of The Baltimore Sun reports.
Basallo sustained the injury when he struck out swinging in the ninth, though Orioles manager Craig Albernaz said after Saturday's game that Basallo would have batted again if the order came up. That should mean that Basallo is in the lineup for Sunday's series finale against Toronto, but if he's unable to play, then Tyler O'Neill could serve as the team's designated hitter. Basallo went 1-for-2 with two walks in Saturday's win.