Diamondbacks vs Astros Prediction, Odds, Moneyline, Spread & Over/Under for July 21

Odds updated as of 3:12 p.m.

The Monday schedule in MLB includes a matchup between the Arizona Diamondbacks and the Houston Astros.

We've got you covered, in terms of the vital information about this game before you take a look at the MLB odds and spreads on FanDuel Sportsbook.

Diamondbacks vs Astros Game Info

• Arizona Diamondbacks (50-50) vs. Houston Astros (57-42)
• Date: Monday, July 21, 2025
• Time: 9:40 p.m. ET
• Venue: Chase Field -- Phoenix, Arizona
• Coverage: ARID and SCHN

Diamondbacks vs Astros Odds & Moneyline

• All MLB odds, betting lines and prop bets are available on FanDuel Sportsbook.
• Moneyline: ARI: (-142) | HOU: (+120)
• Spread: ARI: -1.5 (+138) | HOU: +1.5 (-166)
• Total: 9 -- Over: (-104) | Under: (-118)

Diamondbacks vs Astros Probable Starting Pitchers

Probable Pitchers: Zac Gallen (Diamondbacks) - 7-10, 5.40 ERA vs Colton Gordon (Astros) - 3-2, 4.67 ERA

The Diamondbacks will give the nod to Zac Gallen (7-10, 5.40 ERA), who is eyeing win No. 8 on the season, and the Astros will turn to Colton Gordon (3-2, 4.67 ERA). When Gallen starts, his team is 8-12-0 against the spread this season. When Gallen starts a game and his team is the favorite on the moneyline, they have a record of 5-7. The Astros are 5-5-0 ATS in Gordon's 10 starts with a set spread. The Astros have played while the underdog on the moneyline for four of Gordon's starts this season, and they won all of the games.

Diamondbacks vs Astros Prediction & Pick

All MLB win probability predictions and picks are according to numberFire.
Prediction: Diamondbacks win (50.7%)

Diamondbacks vs Astros Moneyline

• The Diamondbacks vs Astros moneyline has Arizona as a -142 favorite, while Houston is a +120 underdog on the road.

Diamondbacks vs Astros Spread

• The Diamondbacks are hosting the Astros and are favored by 1.5 runs on the spread. The Diamondbacks are +138 to cover the runline, with the Astros being -166.

Diamondbacks vs Astros Over/Under

• Diamondbacks versus Astros on July 21 has an over/under of 9 runs, with the odds on the over -104 and the under set at -118.

Bet on Arizona Diamondbacks vs. Houston Astros on FanDuel today!

Diamondbacks vs Astros Betting Trends

• The Diamondbacks have won in 32, or 50.8%, of the 63 contests they have been named as odds-on favorites in this year.
• Arizona has a record of 17-14 in contests when oddsmakers favor them by -142 or more on the moneyline.
• Contests with the Diamondbacks have gone over the total set by bookmakers in 52 of 97 chances this season.
• In 97 games with a line this season, the Diamondbacks have a mark of 47-50-0 against the spread.
• The Astros have won 60% of the games this season they were the underdog on the moneyline (18-12).
• When playing as a moneyline underdog with odds of +120 or longer, Houston has gone 7-1 (87.5%).
• The Astros have played in 98 games with an over/under set, and have combined with their opponents to go over the total 42 times (42-54-2).
• The Astros have covered 51% of their games this season, going 50-48-0 against the spread.

Diamondbacks Player Leaders

• Geraldo Perdomo has an OPS of .793, fueled by an OBP of .373 to go with a slugging percentage of .420. He has a .272 batting average, as well.
• Among qualifying hitters in the majors, he ranks 54th in batting average, 17th in on-base percentage, and 85th in slugging.
• Perdomo hopes to build on a three-game hitting streak in this matchup. During his last five outings he is hitting .333 with a triple, three walks and seven RBIs.
• Eugenio Suarez leads Arizona with 92 hits. He is batting .257 this season and has 53 extra-base hits. He's also slugging .601 with an on-base percentage of .328.
• Among qualified hitters, his batting average places him 84th, his on-base percentage 77th, and his slugging percentage fourth.
• Suarez has picked up a hit in five games in a row. In his last five games he is batting .500 with a double, six home runs, four walks and 10 RBIs.
• Josh Naylor has collected 98 base hits, an OBP of .361 and a slugging percentage of .452 this season.
• Corbin Carroll has 21 home runs, 48 RBI and a batting average of .251 this season.
• Carroll takes a two-game hitting streak into this matchup. In his last five games he is hitting .261 with two doubles, three triples, a walk and an RBI.

Astros Player Leaders

• Jose Altuve has a .465 slugging percentage, which leads the Astros. He's batting .278 with an on-base percentage of .338.
• Including all qualified players in the big leagues, he is 43rd in batting average, 62nd in on-base percentage and 47th in slugging percentage.
• Yainer Diaz is hitting .239 with 11 doubles, a triple, 13 home runs and 14 walks. He's slugging .394 with an on-base percentage of .271.
• Including all qualifying players, he is 121st in batting average, 154th in on-base percentage and 110th in slugging percentage.
• Cam Smith is hitting .270 with 17 doubles, two triples, seven home runs and 27 walks.
• Christian Walker is hitting .227 with 12 doubles, a triple, 13 home runs and 25 walks.

Sign up for FanDuel Sportsbook and FanDuel Daily Fantasy today!