The Arizona Diamondbacks are returning home after a grinding 2-6 road trip to Mexico, Milwaukee, and Chicago that dropped their season record to 16-17. They have a -31 run differential, and the rotation's 5.42 ERA is the highest in MLB .

The Pittsburgh Pirates are a much-improved team. They come in with a 19-16 record and a +31 run differential. They finally have an offense that can support their excellent young pitching staff, posting a team 105 OPS+ through Saturday's games.

When most pundits looked at the schedule before the season started, they probably thought this would be a softer spot in the schedule for D-backs. But now they'll face the sharp end of the stick in the Pirates rotation, at least in games two and three of the series.

D-backs-Pirates Starting Pitching Matchups

Tuesday, May 5, 6:40 p.m.…