The Twins say Hughes suffered a right shin contusion and is day to day.
White Sox slugger Adam Dunn led off the fourth with a sharp chopper right back at Hughes. The starter had no chance to get out of the way before it plunked him on his leg, and Hughes was immediately stunned by the impact.
Dunn reached on an infield single and Hughes tried to walk it off. But after several minutes he crouched behind the mound and after talking to Twins trainers, Hughes limped off the field.
Hughes has been the Twins' best starter this season. He entered the game with a 10-6 record and 4.06 ERA.
Information from the Associated Press was used in this report.