Desperate Diamondbacks Cling to Playoff Hope Behind Zac Gallen

With their playoff hopes on life support, the Arizon Diamondbacks will look for an ace-like performance from Gallen.

Arizona Diamondbacks pitcher Zac Gallen (23) prepares to face the Texas Rangers in the first inning at Chase Field on Sept. 3, 2025. | Rob Schumacher/The Republic / USA TODAY NETWORK via Imagn Images

The Arizona Diamondbacks face the Philadelphia Phillies on Saturday night with their Postseason aspirations hanging by the thinnest of threads.

Following their 8-2 loss on Friday night they now trail the New York Mets by 3.0 games and the Cincinnati Reds by one game in the NL Wild Card Chase. The Reds hold the tie-breaker, so in effect, they trail the Reds by two games.

While a loss in this game would not eliminate them mathematically, it would put them in such a big hole that it will be near impossible to climb out of. They May already be in that position. Here is a chart that illustrates that point.

Diamondbacks vs Mets and Reds Records | Jack Sommers

Arizona will turn the ball over to Zac Gallen in hopes that he can deliver a much-needed shutdown start against a very tough and hot Phillies lineup.

Diamondbacks and Phillies Pitching Matchup

Aaron Nola and Zac Gallen Pitching Stats | Jack Sommers

Not only has Aaron Nola posted and ERA well over six this year, but he has a career 6.16 ERA against the Diamondbacks in the regular season.

Ironically, one of his few good starts this season came on May 3 against the D-backs in Philadelphia when he tossed six shutout innings. Nola was 1-1 with a 3.48 ERA against the D-backs in the 2023 NLCS.

Nola was never especially dependent on velocity, but both his four-seam and sinker are down about one MPH this year. His walk rate is up to 2.9 batters per nine innings. While that is still better than average, it's significantly higher than the 1.9 BB/9 he registered over the previous four seasons.

The 32-year-old veteran is in the second year of a seven-year, $172 million contract that takes him through age 37 in 2030. With the deterioration of both Nola's peripherals and results, this contract has the potential to be an albatross in the future.

Zac Gallen has turned his season around since the trade deadline, going 5-2 with a 2.68 ERA over his last nine starts. His FIP (Fielding Independent Pitching) is over a run higher however at 3.82.

Gallen did not pitch in Philadelphia earlier this year. He's had plenty of regular season success against them, giving up just three runs in 17 innings over his last three starts versus the Phillies. Gallen faced them twice in the 2023 NLCS and was hit very hard, giving up nine runs on 14 hits in 11 innings.

Gallen will be a free agent at the end of 2025. He is almost certain to receive (and reject) a qualifying offer worth approximately $22 million. But before he gets there his team is depending on him to deliver a good start against his Postseason nemesis and keep the D-backs in the Wild Card chase.

Diamondbacks vs Phillies Lineup

D-Backs lineup today pic.twitter.com/WXfsn4nS6O

— Jack Sommers (@shoewizard59) September 20, 2025

Diamondbacks and Phillies Bullpens

Ryne Nelson was only able to give his team five innings on Friday, leaving 12 outs to get on the table for his bullpen. Three relievers, Jalen Beeks, Taylor Rashi, and Philip Abner got six of those outs, allowing one run.

Jake Woodford came in to pitch the eighth and gave up a two-run homer. Then he allowed three more to score in the ninth as the Phillies blew the game open.

Ryan Thompson, Andrew Saalfrank, and Nabil Crismatt all had the night off. Brandyn Garcia and Juan Morillo both warmed up, but neither got in the game.

The Phillies used a piggyback system Friday, pulling Taijuan Walker after four innings and handing it to Walker Buehler. He went another 3.2 innings. That left just four outs for the Phillies' pen to pick up, and they did so using only two pitchers. They'll have a full compliment of relievers available Saturday.