Diaz is expected to be placed on the 10-day injured list Tuesday due to a left oblique injury, Brian McTaggart of MLB.com reports.
Diaz was scratched from the starting lineup ahead of Monday's 8-3 loss to the Dodgers due to what had been referred to as a left abdominal injury, but Astros manager Joe Espada clarified after the game that the backstop will miss some time due to an oblique issue. Christian Vazquez can be expected to serve as the primary catcher while Diaz recovers.