Montgomery is on the 7-day injured list at Single-A Fresno with an undisclosed injury.
He missed three weeks earlier this season with a quad injury, returned for two games May 17 and 18 before landing back on the injured list May 19. It's possible Montgomery re-injured his quad. He hit .333 with 13 strikeouts, zero walks, one home run and two steals in his most recent 10 games at Single-A.