Minor-league catcher Tuffy Gosewisch will be recalled to take Montero's spot on the roster. The team also optioned reliever Chaz Roe, and the recently-acquired Joe Thatcher will join the team to take his spot (via Diamondbacks Twitter account).
Montero, 30, has batted .228/.316/.345 in 2013, well below his career line of .268/.346/.434.
Roe, 26, has a 5.79 ERA in 4 2/3 innings pitched for Arizona this season. Thatcher was recently acquired from the Padres as part of the Ian Kennedy trade, and he has an ERA of 2.10 in 30 innings pitched.
Gosewisch, 29, hit .285/.321/.456 for Triple-A Reno, which is a notorious hitter-friendly ballpark. If Montero is to miss significant time, Arizona could look to pick up a better alternative outside the organization before the waiver deadline.
The Diamondbacks are currently 55-53, and in second place in the National League West.