Nats righty Josiah Gray's ERA of 3.09 looks pretty good, but his WHIP of 1.42 is concerning and his xFIP is 4.96 which suggests that he's been lucky and that regression is coming.

Diamondbacks righty Merrill Kelly (7-3, 2.80 ERA) is having a solid year, and he is 4-0 with an ERA of 1.63 on the road.

Washington is only 12-21 at home, while Arizona is 17-11 on the road.

8* PLAY ON ARIZONA DIAMONDBACKS.