Minnesota Twins starter P.J. Walters left Wednesday's game against the Philadelphia Phillies with right shoulder stiffness.
He surrendered four consecutive singles without recording an out before exiting. In all, he was charged with four runs.
Entering Wednesday's contest, the 27-year-old Walters had a 2-1 record with a 4.42 ERA over six starts.
Jeff Manship replaced Walters on the mound.