"Just what it looks like," said a smiling Eaton, who had the sore area wrapped postgame. "Usually I can kind of shake them off, but I couldn't really move my arm, my hand up and down.
"X-rays were all good. Everything went clear there. It's just strength, getting it back, getting some movement back, and [I'll] be good to go."
Walker hit Eaton once and Jose Abreu twice in the contest. Eaton leads the White Sox with 12 stolen bases, ranks second with 67 runs scored and 138 hits and has played Gold Glove-caliber defense in right and center.
"As of right now, he's just day to day," White Sox manager Robin Ventura said.
Scott Merkin has covered the White Sox for MLB.com since 2003. Read his blog, Merk's Works, follow him on Twitter @scottmerkin, on Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.