What It Means:

Jeff Mathis was only just activated from the disabled list at the end of September, but the Diamondbacks are electing to go with him behind the plate for tonight's winner-take-all. Mathis caught all of starter Zack Greinke's games prior to missing over a month with an avulsion fracture in his right hand.

Mathis is known more for his defense, so Iannetta could make an appearances as a pinch-hitter if necessary. Iannetta has a .367 wOBA this season, and his 17 home runs are his most since 2008.