Washington Nationals vs St. Louis Cardinals Picks and Prediction for Sunday September 20 2026

The Washington Nationals visit the St. Louis Cardinals at Busch Stadium in St. Louis, Missouri, on Sunday, September 20, 2026. First pitch is scheduled for 2:15 PM ET with coverage on MLB.TV. Washington enters at 72-82 overall and 35-41 on the road, while St. Louis is 75-79 overall and 37-42 at home. The Nationals won the only completed game of the current series 9-1 on Friday and have won four of their last five completed games. St. Louis has dropped three straight completed games and sits 21 games behind Milwaukee in the NL Central. At the time of this writing the odds were not released. Be sure to check out our free MLB picks for more MLB predictions throughout the season.

Starting Pitchers

Washington is scheduled to start Jake Irvin, who enters at 2-9 with a 5.51 ERA and 1.41 WHIP through 96.1 innings. Irvin has allowed 90 hits and 17 home runs while recording 96 strikeouts against 46 walks. St. Louis counters with Quinn Mathews, who is 2-3 with a 3.62 ERA and 1.39 WHIP through 37.1 innings. Mathews has surrendered 36 hits and only three home runs while striking out 36 and walking 16. St. Louis has the starting-pitching advantage based on the available numbers. The WHIPs are nearly identical, but the Cardinals' starter owns an ERA nearly two runs lower and has been considerably better at keeping the ball in the park.

Washington's Offense Has Been the Difference

Washington enters Sunday with a 72-82 record and a 35-41 mark away from home. The Nationals have won four of their last five completed games, including Friday's 9-1 victory at Busch Stadium. Over those five contests, Washington has scored 27 runs while allowing only 17. Three of the four victories have come by multiple runs, and the Nationals have scored at least six runs in each of their four wins during this stretch.

Washington's season-long offensive numbers are substantially stronger than its overall record might suggest. The Nationals are batting .247 with 1,296 hits, 787 runs and 201 home runs. They carry a .323 on-base percentage and .426 slugging percentage. Pitching has been the weakness, with Washington posting a 4.69 ERA and 1.39 WHIP while allowing opponents to hit .253. The staff has issued 573 walks against 1,206 strikeouts.

The contrast between Washington's offense and pitching creates an interesting matchup. The Nationals have scored 93 more runs and hit 43 more home runs than St. Louis while also owning the better batting average, on-base percentage and slugging percentage. Their 4.69 team ERA is the major concern, particularly with a struggling starter scheduled for Sunday. Washington may need its offense to compensate again, but recent results suggest it is capable of doing exactly that.

St. Louis Needs Its Pitching Edge to Hold Up

St. Louis enters at 75-79 overall and surprisingly has struggled at Busch Stadium, where the Cardinals are 37-42. They have gone 2-3 across their last five completed games, scoring 14 runs while surrendering 27. More concerning is the recent direction of those results. St. Louis has lost three consecutive completed games, allowing 25 runs during that skid, including nine in Friday's series-opening loss to Washington.

The Cardinals are batting .242 with 1,257 hits, 694 runs and 158 home runs. St. Louis has a .316 on-base percentage and .381 slugging percentage, leaving it behind Washington across every major offensive category provided. The pitching numbers are better. The Cardinals own a 4.30 ERA and 1.36 WHIP with 538 walks and 1,222 strikeouts while opponents are batting .254.

Sunday's matchup therefore puts pressure on the St. Louis pitching staff. The Cardinals have neither the offensive production nor the home-field results to make them an automatic choice despite having the better overall record. Their clearest advantage is the scheduled starting matchup, and they need to capitalize on it. If Washington can get into the middle innings without falling into a significant deficit, its superior offensive numbers could become increasingly important.

Washington Nationals vs St. Louis Cardinals Picks and Prediction

Pick: Washington Nationals Moneyline

Washington is the preferred side despite entering with the weaker starting-pitching numbers. The Nationals have been the substantially better offensive team, scoring 787 runs compared with 694 for St. Louis while holding advantages in batting average, on-base percentage, slugging percentage and home runs. Washington has also won four of its last five completed games and just defeated St. Louis 9-1 at Busch Stadium. St. Louis has a starting-pitching edge and ESPN's supplied matchup predictor favors the Cardinals, but a 37-42 home record combined with the large offensive disparity makes Washington the more attractive side at a reasonable moneyline price.

Pick: Over 8.5 or Lower

The Over 8.5 or lower is the preferred total target. Washington's scheduled starter carries a 5.51 ERA and 1.41 WHIP, creating an opportunity for a St. Louis offense that has struggled recently to generate more production. On the other side, Washington has scored 27 runs across its last five completed games and owns 201 home runs with a .426 slugging percentage for the season. The Nationals' 4.69 team ERA also increases the possibility that both clubs contribute to the scoring. With Washington possessing the stronger offense but St. Louis holding the more favorable starting-pitching matchup, 8.5 is a reasonable ceiling for an Over play.

Final Picks: Washington Nationals Moneyline and Over 8.5 or Lower

This preview was completed on Saturday, September 19, 2026. Starting pitchers, betting lines and other game information are subject to change before the game begins.