Philadelphia Phillies at Arizona Diamondbacks Prediction and Picks – September 21, 2025

The Arizona Diamondbacks (78-77) host the Philadelphia Phillies (92-63) in the finale of a three-game set on Sunday. Philadelphia rolled to an 8-2 win Friday before Arizona answered with a 4-3 victory on Saturday night.

If you want the Phillies vs. Diamondbacks prediction, read on and check out our MLB Predictions to beat the sportsbooks!

World Series favorites

The Philadelphia Phillies have already clinched the NL East and are still battling the Milwaukee Brewers for the league’s best record. According to ESPN Bet, Philadelphia sits as the current World Series favorite at +450.Ranger Suárez takes the ball on Sunday. He’s been excellent in 2025, posting a 12-6 record with a 2.84 ERA and 1.17 WHIP. On the road, Suárez has been even sharper, carrying a 2.25 ERA over his last 11 starts.

At the plate, Philadelphia has power everywhere. Kyle Schwarber remains the primary source of thunder with 53 homers, 129 RBI, and a .369 OBP. Trea Turner, sidelined by a hamstring injury, still leads the team with a 5.3 WAR and .305 average.

Diamondbacks still in contention

Arizona hasn’t been mathematically eliminated and sits just two games back of a wild-card berth with seven games left. The D-backs have kept their season alive by winning five of their last seven.

Eduardo Rodríguez gets the nod Sunday. He’s 8-8 with a 5.12 ERA and has been shaky at home (5.56 ERA), but Arizona has managed to win his last four home starts.

Despite trading Eugenio Suárez and Josh Naylor before the break, the lineup has held steady. Geraldo Perdomo leads the team with a 6.8 WAR, hitting .289 with 19 homers, 97 RBI, and 26 stolen bases. Corbin Carroll has delivered 30 homers, 76 RBI, and 29 steals while adding a 5.2 WAR.

Predictions

Moneyline Pick:

• Diamondbacks +110 (4 units)

On paper, this feels like a bargain on Philadelphia with the better pitcher and the World Series favorites. But the Phillies have little left to play for, while Arizona is clinging to postseason hopes in a must-win spot.

Rodríguez is battle-tested, and Arizona has won his last four home starts. More importantly, the active Diamondbacks lineup owns a .384 lifetime batting average (33-for-86) against Suárez. That includes his rough Opening Day outing when he allowed seven earned runs in just 3.2 innings. Even though Suárez has been strong lately with six straight wins, this is a letdown spot against a lineup that has consistently tagged him. The motivational edge makes Arizona a nice plus money play.

Total Pick:

• Over 8.5 (4 units)

The number is high with Suárez on the mound, but history matters. He’s 1-3 with a 6.23 ERA lifetime against Arizona, and his struggles versus this lineup can’t be ignored. Pair that with Rodríguez’s inconsistency and a shaky Diamondbacks bullpen, and the setup favors runs. A pitchers’ duel is unlikely, back the over.