Philadelphia Phillies vs Arizona Diamondbacks Prediction, Odds and Picks for Today, 09/20/25

With the NL East already locked up, the Phillies aren’t easing off against the Diamondbacks. Arizona sits just three games out of the final NL Wild Card spot, and Philadelphia knows the danger this team can pose – and they don’t want a repeat of what happened in 2023 where the Diamondbacks defeated the Phillies in the NLCS. 

The Phillies will send Aaron Nola to the mound who enters with a 4-9 record and a 6.44 ERA. For the Diamondbacks, Zac Gallen will get the nod, entering with a 12-14 record and a 4.73 ERA. Gallen’s recent numbers are significantly better than what his season totals show. In his last four starts, he’s 3-1 with a 2.19 ERA and he’ll look to slow down this Phillies offense in tonight’s matchup. Offensively, the Phillies are averaging 6.8 runs per game compared to the Diamondbacks 4.9. Despite the difference in offense, I think the Diamondbacks will get to Nola early and Gallen can limit the damage done by the Phillies, making Arizona my best bet of the day. 

Phillies vs Diamondbacks prediction: Diamondbacks ML (-115) available at time of publishing. Playable at that number.