High-stakes September showdowns that will define MLB season

The NFL kicks off its season Sept. 5, but don’t sleep on Major League Baseball. With playoff races heating up, the diamond is where the action is — especially with games every day.

With so much on the line, from division battles to wild-card duels, this month will shape the postseason and provide must-watch baseball.

Here’s a look at the most compelling matchups that will define the final stretch of the season. (All statistics through games on 8/28.)

Dodgers at Diamondbacks (Friday-Monday): Los Angeles heads to Arizona in what promises to be a crucial divisional showdown. Both teams are vying for NL West supremacy, making this series a must-win for the D-backs, who trail the Dodgers by three games in t. The Diamondbacks haven't won the NL West since 2011, while the Dodgers have captured the division ten of the last eleven seasons.

Red Sox at Mets (Monday-Wednesday): This under-the-radar series carries heavy playoff implications. Boston—who hasn't been in the postseason since 2021—is just three games back in the AL wild-card race, while the Mets, looking to return to the postseason for the first time since 2022, trail by four games in the NL. A bad series could crush either team’s playoff hopes.

Diamondbacks at Astros (Sept. 6-8): Arizona faces a tough road series in Houston. The D-backs need to keep pace in the NL wild-card race, especially if they falter against the Dodgers, while the Astros look to fend off Seattle in the AL West. The D-Backs also hope to have Corbin Carroll and Ketel Marte back in time for the series.

Mariners at Cardinals (Sept. 6-8): Seattle visits St. Louis in a critical series for both teams. The Mariners are chasing Houston, sitting 3.5 games back after blowing a 10-game division lead earlier in the season. The Cardinals, meanwhile, cling to slim playoff hopes, seven games behind in the NL wild card.

Royals at Yankees (Sept. 9-11): All eyes will be on the Bronx as Kansas City and New York square off. With the AL MVP race between Bobby Witt Jr. and Aaron Judge heating up, this series is about more than just wins and losses, although those will matter plenty too. They Yankees find themselves in a battle with the Orioles atop the AL East while the surging Royals are looking to make history .

Mets at Phillies (Sept. 13-15): If the Mets are still in the race, they’ll need to make up ground in this divisional battle against Philadelphia. A sweep could turn the tide for New York.

Mariners at Astros (Sept. 23-25): This is the one to watch. If Seattle is still within striking distance of the division, this series could be their chance to dethrone Houston, which has won the division six of the past seven seasons.

Padres at Dodgers (Sept. 25-26): The Padres have all but locked up a playoff spot, but they’d love to claim the NL West crown by beating their biggest rival. Look for Jackson Merrill to punctuate his rookie season in this divisional showcase.

Orioles at Yankees (Sept. 24-26): The AL East title could come down to this series in the Bronx, with the Yankees currently holding a one-game lead. Baltimore and New York will likely be battling for the best record in the AL and a first-round bye. This series will tell us a lot about how October will be set up.