Sosa will start at third base and bat seventh in Sunday's game against the Dodgers.
Sosa picked up starts in four of the Phillies' first five games of the season, but he shifted back into a utility role after Trea Turner overcame a back issue. Alec Bohm will get a breather Sunday, opening the door for Sosa to re-enter the starting nine after being out of the lineup for the previous three contests.