The St. Louis Cardinals close out their home series against the Washington Nationals on Sunday, September 20, 2026, at Busch Stadium with first pitch scheduled for 2:15 PM ET. Quinn Mathews gets the ball for St. Louis against Washington's Jake Irvin. With the regular season winding down, every game in September carries weight, and the Cardinals will look to take care of business in front of their home crowd before the calendar flips any further toward October.

Pitching Matchup: Quinn Mathews vs. Jake Irvin

Mathews draws the Sunday afternoon assignment, continuing to build on what has been a developing role in the St. Louis rotation. The left-hander has shown flashes of the stuff that made him a prospect worth watching, and a home start at Busch Stadium gives him a familiar environment to work with.

Irvin makes the trip to St. Louis for Washington. The right-hander has been a consistent presence in the Nationals' rotation and is capable of keeping lineups off-balance when his command is sharp. The Cardinals will need to be disciplined early and avoid letting Irvin settle into a rhythm.

Cardinals Starting Lineup

• JJ Wetherholt — 2B
• Iván Herrera — DH
• Alec Burleson — 1B
• Jordan Walker — RF
• Leo Bernal — C
• Thomas Saggese — SS
• Bryan Torres — LF
• José Fermín — 3B
• Nathan Church — CF

Keys to Watch for St. Louis

Jordan Walker in the Middle of the Order

Walker slots into the cleanup spot, and his ability to drive in runners will be central to how the Cardinals' offense functions on Sunday. When Walker is locked in, the middle of this lineup has real damage potential. Burleson hitting third ahead of him gives St. Louis back-to-back threats that Irvin will have to navigate carefully.

JJ Wetherholt Setting the Table

The rookie second baseman leads off and has a direct impact on how many quality at-bats the top of this order generates. Wetherholt getting on base consistently puts pressure on Washington's defense and pitching from the very first inning.

Mathews Keeping Washington Off the Board Early

The formula for a Cardinals win runs through Mathews controlling the game through the first five or six innings. If he can work efficiently and limit walks, the St. Louis bullpen should be in a position to close things out. A short outing from Mathews puts pressure on a bullpen that needs to be managed carefully this late in the season.

Prediction

This is a winnable Sunday afternoon game for the Cardinals at home. Busch Stadium crowds in September have a way of bringing energy to the ballpark, and St. Louis has enough lineup depth to put runs on the board against Irvin if they stay patient at the plate. Give the edge to the Cardinals, 4-2, with Mathews delivering a quality start and the middle of the order doing enough damage to get the win.

You can catch the game on Cardinals.TV Presented by bet365 or listen live on KMOX 1120 AM/104.1 FM.