PHOENIX — August is coming to a close, but the Arizona Diamondbacks are preparing for possibly one of their biggest series of the season, one that will test their grit and chemistry with postseason implications at stake.
Apr 12, 2026; Philadelphia, Pennsylvania, USA; Arizona Diamondbacks infielder Nolan Arenado (28) advances to third against the Philadelphia Phillies in the second inning at Citizens Bank Park. Mandatory Credit: Kyle Ross-Imagn Images
They will open a three-game series against the Philadelphia Phillies, who are also playing to remain in the National League wild-card conversation. Before Monday’s contest, the D-Backs are in the final wild-card spot, while the Phillies hold the second spot.
Arizona is up a half-game on the San Diego Padres after splitting their latest series with the San Francisco Giants last weekend. With September approaching, every game continues to have added significance as the group of contenders continues to get crowded.
Philadelphia isn’t looking to just fall over, either, despite being 4.5 games ahead of the Diamondbacks in the standings. The Phillies have plenty of incentive to gain ground, adding pressure to Arizona to protect its narrow advantage over San Diego.
Then there is Ketel Marte.
Apr 12, 2026; Philadelphia, Pennsylvania, USA; Arizona Diamondbacks infielder Ketel Marte (4) advances to third against the Philadelphia Phillies in the eighth inning at Xfinity Mobile Arena. Mandatory Credit: Kyle Ross-Imagn Images
Marte will be activated this series after his recent leave kept him away from the team and raised questions about his relationship with the organization and his teammates. His return gives the club a significant boost in the lineup, but it will also provide an early look at how the clubhouse responds to having him back.
The second baseman has been one of the most important players in the franchise, and his talent isn’t an issue. But after everything that has unfolded during his absence, returning for a series against a tough opponent in the middle of a race for October will no doubt test how quickly the Snakes can put it all behind them.
And that is what could make this the most important series of the year.
Sep 21, 2025; Phoenix, Arizona, USA; Philadelphia Phillies infielder Bryce Harper (3) singles on a sharp line drive to center in the ninth inning against the Arizona Diamondbacks at Chase Field. Mandatory Credit: Allan Henry-Imagn Images
The Diamondbacks and Phillies already have an unspoken “rivalry” due to the 2023 postseason, and every series since has made it feel like a playoff matchup. However, with positioning on the line and the return of a player who has had teammates and fans split on him, this could be Arizona’s biggest test yet.
There is little room for the D-Backs to stumble with September on the horizon and the Padres just a half-game behind them. A strong series could give Arizona momentum heading into the final month. A poor one could make the wild-card race even tighter.
These are the moments we play for. pic.twitter.com/pQLCmjR622
— Arizona Diamondbacks (@Dbacks) August 31, 2026
As the calendar sets its final day in August and flips into September, this could be the series that defines their season.
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Wendy Lopez is a reporter for Burn City Sports. You can follow her on her X account, @wlopezde
