The veteran right-hander appeared to wince after a pitch to Kurt Suzuki with one out in the third inning. He threw two more pitches and retired Suzuki on a ground ball, but trainer Rick Griffin and manager Eric Wedge immediately headed for the mound.
Millwood went 2 2/3 innings, allowing one run on one hit -- a home run -- while striking out three before exiting the game. Long reliever Hisashi Iwakuma replaced him.
Millwood missed extended time after leaving his June 8 start after six innings due to a strained right groin. The veteran rejoined the rotation eight days later and was making his third appearance on Wednesday since the previous injury.
Josh Liebeskind is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.