White Sox first baseman Paul Konerko was placed on the seven-day disabled list on Friday with a concussion.
Alex Rios, who missed Wednesday's game with a stiff back, is playing right field and batting fourth in Konerko's customary place in the lineup.
Konerko was hit in the right temple area by the Kansas City Royals' Jarrod Dyson during the seventh inning of Tuesday night's game at U.S. Cellular Field. Dyson's left elbow made contact as Konerko, his body positioned toward right field, received a throw from second baseman Gordon Beckham, who had made a diving stop of Dyson's grounder.
Ventura and trainer Herm Schneider came out to check Konerko, who remained in the game. He batted during the eighth inning and struck out.
Ventura said Konerko didn't sleep well Tuesday night and appeared somewhat woozy when he arrived at the ballpark on Wednesday. He missed Wednesday's 2-1 loss to the Royals and was not in the dugout during the game.
"He seems fine but talking to him and having to go play is two different things,'' Ventura said Friday.
"As far as being nauseated and stuff it's not as bad as the other day but he does feel it and has all the symptoms of a concussion.''
Major League Baseball has a seven-day disabled list specifically for concussions.
Konerko, the team's captain and cleanup hitter, is batting .316 with 18 homers and 54 RBI. He made the All-Star team for the sixth time this season.
The Sox will call up a replacement for Konerko on Saturday.