With one out in the eighth, Burnett struck Barney on the left side of his helmet with the first pitch of the at-bat. Barney put both hands on the side of his head and stood at home plate.
Cubs manager Dale Sveum and assistant athletic trainer Ed Halbur immediately went to Barney, and after some conversation, decided to pull the second baseman.
Barney was being tested for a possible concussion. A Cubs spokesperson said they would have test results Wednesday.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.