Oakland A's designated hitter Billy Butler, who sat out the team's Saturday and Sunday games against the White Sox in Chicago, was sidelined with an injury he sustained in an altercation with teammate Danny Valencia, the San Francisco Chronicle reported.
According to the newspaper, no one with the team would confirm or deny the report.
Valencia told the Chronicle after the Athletics' 4-2 loss to the White Sox on Sunday, "No comment. What happens in the clubhouse stays in the clubhouse."
Valencia went 2-for-4 on Saturday, then sat out Sunday.
Manager Bob Melvin said Butler was out because of nausea and vomiting, adding that the player did not have the flu. The Chronicle noted that nausea and vomiting can be symptoms of a concussion.
In 79 games this season, Butler is hitting .286 with a .338 on-base percentage, a .419 slugging percentage, four homers and 30 RBIs. He hasn't played since coming off the bench and going 0-for-1 on Wednesday in Oakland's 6-2 road loss to the Texas Rangers.