Report: Billy Butler in altercation with A's teammate Danny Valencia

— -- A season to forget in Oakland?may have taken an unusual turn as two A's players engaged in an altercation that left one injured, according to a San Francisco Chronicle report.

A's players Billy Butler and Danny Valencia were involved in some sort of clubhouse spat Friday, according to the report. Since then, Butler has missed Oakland's games Saturday and Sunday with what manager Bob Melvin said was nausea and vomiting.

While neither Melvin nor any of his players would confirm the report, Melvin did say Butler's health woes were not related to the flu or any illness.

Valencia, who did not play in Sunday's game, issued a "no comment" about the alleged incident after the Athletics' 4-2 loss to the White Sox, but added, "What happens in the clubhouse stays in the clubhouse."

Butler and Valencia have been teammates in both Kansas City and Oakland in parts of 2014 and 2015 and all of 2016.

Valencia has had the better season of the two, batting .302 with 15 homers in 97 games, while Butler in 79 games is batting .284 with four home runs.

The A's (53-71) have lost seven of their past eight games and are in fourth place in the American League West -- 19? games behind the division-leading Texas Rangers.