Santana was scratched from Thursday's start against the Pirates due to right lat soreness, Eric Stephen of TrueBlueLA.com reports.
Santana was set to make his first career big-league start before the injury cropped up and forced Daniel Hudson to start in his place. The severity of the injury remains unclear at this point, as does a possible timetable for his return. With the Dodgers off the schedule twice next week, the team could move forward with a four-man rotation until June 19 if it chooses.