Jackson, who drove in the winning run Tuesday night, has hit consistently well throughout the season, with a high of .297 in June and a low of .266 in September and October.
"There's really nothing gross that he's doing," said Ausmus. "He's just in a little bit of a funk. I don't think he's expanding the zone."
Jackson has pretty good numbers for May in his career, with the 28 doubles his best of any month and being successful in all 15 of his stolen-base attempts in the month.
Rick Eymer is contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.