Diaz is out of the lineup for Sunday's game against the Red Sox.
While Oakland faced left-handed starting pitchers in four of its past five games, Diaz had started at first base or third base on four occasions, going a collective 4-for-15 during that stretch. He'll be on the bench Sunday versus right-hander Tayler Scott and looks as though he'll be relegated to a utility role for the time being, with most of Diaz's starting opportunities expected to come against southpaws.