San Diego's Matt Waldron is that pitching rarity - a knuckleballer. He's also a hot pitcher with a 1.47 ERA during his last three starts. Waldron, a righty, hasn't permitted more than two earned runs a game during his past five starts. The Diamondbacks rank in the bottom-10 against righthanders in batting average, slugging percentage and OPS.

Arizona starter Ryne Nelson is in good form, too, with a 2.89 ERA in his last three starts. Nelson has been much more effective on the road than at home. Before breaking through with 10 runs on Friday night, the Padres had been averaging just 2.2 runs in their last five games.

Note, too, the venue and scheduled home plate umpire, Tripp Gibson. Petco Park is the premier pitching park in the league. Gibson is a good Under umpire. The Under has cashed 56 percent of the time during his last 139 games behind the plate.