Houston Astros vs Arizona Diamondbacks Prediction 07/21/2025 Picks

In this article, we will formulate an Astros vs Diamondbacks prediction for this MLB game on Monday, July 21, at Chase Field in Phoenix, Arizona. Let’s take a look at the prediction for this MLB matchup.

Houston Astros Betting Preview

The Houston Astros (57-42, 24-23 Away) were swept by the Cleveland Guardians and lost a series to the Texas Rangers to close the first half of the season. They didn’t start the second half on a high note, losing two of three games to the Seattle Mariners. At least, the Astros avoided getting swept with an 11-3 win in Game 3 on Sunday. Victor Caratini and Taylor Trammell led the offense with three RBI apiece, while Hunter Brown pitched for 4.0 innings in a no-decision, allowing three runs on six hits with seven strikeouts and two walks. Kaleb Ort was credited with the win.

This season, the Astros average 4.40 runs per game (15th in the MLB) on a .258/.323/.409 triple-slash. When it comes to pitching, the Astros’ staff has a 3.64 ERA (6th) and 1.17 WHIP (2nd). Jose Altuve leads the Astros with a .278 batting average, 17 home runs, and 53 RBI this season.

Colton Gordon will take the mound for the Astros on Monday. The 26-year-old left-hander has a 3-2 record in ten starts this year with a 4.67 ERA and 1.42 WHIP in 52.0 innings.

Arizona Diamondbacks Betting Preview

The Arizona Diamondbacks (50-50, 26-25 Home) were winless in five straight series, but opened the second half of the season with a sweep of the St. Louis Cardinals at home. Arizona allowed only seven runs in three games and clinched the series with a 5-3 victory on Sunday. Eugenio Suarez led the offense with two homers and four RBI, while Merrill Kelly got the win after allowing two runs on three hits with five strikeouts and four walks across 6.0 innings of work.

This year, the Diamondbacks average 5.15 runs per game (4th in the MLB) on a .252/.329/.448 triple-slash. When it comes to pitching, the Diamondbacks’ staff has a 4.58 ERA (25th) and 1.33 WHIP (23rd). Eugenio Suarez leads the Diamondbacks with a .257 batting average, 35 home runs, and 85 RBI this season.

The projected starting pitcher for the Diamondbacks is Zac Gallen, who is 7-10 in 20 starts this season, with a 5.40 ERA and 1.37 WHIP in 115.0 innings.

Total Runs Facts

Ten of the Diamondbacks’ last 11 night games against American League opponents have gone OVER the total runs line.
Five of the Astros’ last six road games after playing the previous day have gone OVER the total runs line.
The ‘Inning 1 OVER 0.5 runs’ market has hit in 10 of the Diamondbacks’ last 11 night games against American League opponents.
The ‘Inning 1 UNDER 0.5 runs’ market has hit in each of the Astros’ last four road games.

Matchup/League Facts

The Diamondbacks rank 2nd in the league for slugging percentage this season (.448).
The Diamondbacks rank 3rd in the league for RBIs this season (503).
The Astros rank T1st in the league for hits allowed this season (738).
The Astros rank 2nd in the league for batting average this season (.258).

Astros vs Diamondbacks Prediction

The Astros won seven of the previous ten H2H encounters, including five of the last six. The past three duels went Over, and I am backing another Over in this one because I am not impressed with the way Colton Gordon and Zac Gallen are playing lately. Gordon was excellent in June, but allowed nine runs in two starts in July, and the D-backs, who have one of the best offenses in MLB, will do damage early on. Gallen, on the other hand, surrendered 4+ runs in five of his previous seven starts, including the most recent one against the Angels, when he allowed six runs in 5.0 innings. Back the Over.