An altercation between Oakland teammates Billy Butler and Danny Valencia was the cause of Butler's absence over the team's past two games, sources confirmed to MLB.com's Jane Lee. The San Francisco Chronicle originally reported the incident.
Both players and management declined to comment on the altercation. On Saturday, A's manager Bob Melvin told reporters that Butler would sit out because of nausea and vomiting and ruled out the flu as a cause of those symptoms. Valencia also sat out Sunday's 4-2 loss for Oakland in its series finale against the White Sox.
Butler and Valencia played briefly together on the 2014 American League champion Royals and have been teammates in Oakland since August of last year.