The Washington Nationals and St. Louis Cardinals close their weekend set at Busch Stadium on Sunday afternoon, with the market pricing a modest home favorite. St. Louis sits at -147 on the moneyline, and the total is posted at 9. Neither club has anything left in the standings. Still, Saturday’s 11-inning marathon left a mark, and our headline play comes from what happens after the starters walk off.
Last Updated: Sunday, September 20, 2026
Washington Nationals vs. St. Louis Cardinals — Time & How to Watch
| Where | Busch Stadium, St. Louis, Missouri |
| When | Sunday, September 20 — 2:15 PM ET |
| TV | Nationals.TV, Cardinals.TV, MLB.TV |
Washington Nationals vs. St. Louis Cardinals Betting Preview
The pitching matchup starts this game, and on paper it is lopsided. St. Louis hands the ball to rookie left-hander Quinn Mathews, 2-3 with a 3.62 ERA through seven big league starts. Washington counters with right-hander Jake Irvin, listed as the Sunday probable at 2-9 with a 5.51 ERA. That gap explains most of the price.
Mathews has been sharp lately. Over his last three starts he has allowed three earned runs in 17.2 innings, including a 6.2-inning, eight-strikeout effort against San Francisco. However, the command is shakier than the ERA suggests. He has walked 16 in 37.1 innings and has never finished a seventh inning in the majors.
Irvin’s season has been a grind. He carries a WHIP just over 1.40 and has not completed six innings since mid-August. More telling is how Washington has used him. On September 13 the Nationals pulled him from the conventional rotation slot and sent him out behind an opener, and he threw five innings with six strikeouts in that role. He starts here, but the handling says plenty about expected length.
Team form cuts the other way. Washington enters at 73-82 and has won six of its last seven, a run that followed a seven-game losing streak. St. Louis is 75-80 and has dropped four in a row, the latest an 8-5 loss in 11 innings on Saturday. Both bullpens emptied out in that one. Sunday is a day game after it.
Washington Nationals vs. St. Louis Cardinals Odds
| Run Line | Moneyline | Total | |
|---|---|---|---|
| Nationals | +1.5 (-165) | +123 | U 9 (-105) |
| Cardinals | -1.5 (+140) | -147 | O 9 (-115) |
Odds accurate as of September 20, 2026 via TheSpread.com. Odds change, get the latest MLB Odds – Futures – Props
Washington Nationals vs. St. Louis Cardinals — Who Is the Public Betting?
| Nationals | 26% | 74% | Cardinals |
See the latest MLB Public Betting Splits and make smarter wagers!
Nationals vs. Cardinals Prediction — Runs Galore at Busch?
Start with the bullpens, because that is where this game gets decided. Saturday went 11 innings. St. Louis rode Gordon Graceffo deep into extras, and Washington needed Riley Cornelio for an inning and two-thirds before Will Dion closed it. Neither manager arrives at a matinee with a rested set of late-inning arms. That is not a projection. It already happened.
Now layer the starters on top. Mathews has never pitched past 6.2 innings and walks close to four per nine. Irvin has not finished six innings in over a month. Both sides likely turn the game over to relief work by the sixth. Short starts plus tired relievers pushes run expectation above what the posted number implies. Washington also put up eight runs in this park on Saturday.
The market nudges the same way, quietly. The moneyline and run line have not moved a cent since they opened. The only shift came on the total, where the juice tilted off an even split — and not the way a low-scoring projection would suggest. That is soft confirmation, not loud. The counter-case is real: Mathews has been excellent for three turns, and a rookie with a hot hand can carry a pressing lineup.
The Pick: Over 9 (-115)
Nationals vs. Cardinals Prediction — Dog too Good to Pass?
Roughly three-quarters of the run-line tickets and 72% of the moneyline tickets sit on St. Louis. Ordinarily that one-sided action drags a home price higher. Here it has done nothing. A frozen line under heavy public money is one of the quieter signals in handicapping, and it usually points at the side nobody is buying. The window since this line opened is short, so treat it as a modest lean.
Form supports the same side. Washington has won six of seven and has already taken the first two games of this series. St. Louis has lost four straight. In contrast, the case against is the whole reason for the price. Mathews has been the better pitcher this month, and a road team starting the man with the 5.51 ERA is exactly the profile that usually deserves to be an underdog. This is a live dog in a reliever-decided game, not a mispriced favorite.
The Pick: Nationals Moneyline (+123)
Final Thoughts and Bonus Angle
One angle worth flagging is the one we passed on. A first-five-innings play is the natural vehicle when the edge is purely about the starting pitchers, and that is not the case here. This edge sits in the seventh inning and later, where two depleted bullpens must cover outs. That argues for the full game rather than the shortened market.
Watch two things. The first is Mathews’ pitch count through four. He walked four in a start this month, and early traffic forces St. Louis to the phone before the sixth. The second is which arms are genuinely available after Saturday. If either manager reaches for a long man in a close sixth, the run environment changes fast.
For more on this series, see our Nationals vs. Cardinals prediction for September 19 and our latest NL Central picks coverage.
Recapping the card: Over 9 (-115) is the strongest play, and the Nationals moneyline (+123) is the secondary lean.
MLB Nationals vs. Cardinals FAQ: Sunday September 20, 2026
What time does the Nationals vs. Cardinals game start?
First pitch is set for 2:15 PM ET on Sunday, September 20, 2026. It is a day game and the finale of a three-game weekend series. The clubs played 11 innings on Saturday, so both rosters turn around on short rest.
What channel is the Nationals vs. Cardinals game on?
The game airs on Nationals.TV for Washington viewers and Cardinals.TV for St. Louis viewers, with an out-of-market stream on MLB.TV. There is no national broadcast window. Availability depends on your location relative to each club’s home television territory.
Who is pitching for the Cardinals today?
Left-hander Quinn Mathews is the listed probable starter for St. Louis. The rookie is 2-3 with a 3.62 ERA and 36 strikeouts in seven starts this season. Washington counters with right-hander Jake Irvin, who is 2-9 with a 5.51 ERA.
Where are the Nationals and Cardinals playing today?
The game is at Busch Stadium in St. Louis, Missouri, with Washington as the road club. It closes the Cardinals’ final home stand of the 2026 regular season. The Nationals took the first two games of the series at the same venue.
Who won the last meeting between the Nationals and Cardinals?
Washington won 8-5 in 11 innings on Saturday, September 19, scoring four runs in the top of the 11th to break a tie. The rally included a catcher’s interference call with the bases loaded. The win moved the Nationals to 73-82 and dropped St. Louis to 75-80.