We may have caught a glimpse of said discomfort on this play:
McCutchen also reacted gingerly after a swing at one point Tuesday.
Remember, McCutchen earlier this month spent time on the disabled list due to an avulsion fracture involving the costochondral cartilage of the left 11th rib. He has obviously returned from the injury, but he's still playing through it. On Sunday, he said that he wasn't 100 percent, but was feeling good enough to play (via triblive.com).
McCutchen is hitting .307/.403/.539 with 32 doubles, 20 homers, 70 RBI and 17 stolen bases. With his team right in the thick of the NL wild-card race in the final days of August, it's easy to see why the 2013 NL MVP is trying to play through an obvious injury.