Astros vs. Marlins Prediction, Odds, Probable Pitchers and Prop Bets for Monday, Aug. 4

The Marlins are favored at home with Sandy Alcantara on the mound.

The Miami Marlins are favored with starting pitcher Sandy Alcantara on the mound. / Sam Navarro-Imagn Images

The Houston Astros have seen the lead atop the AL West dwindle as of late, as they’ve dropped eight of their last 10 games heading into Monday’s series opener with the Miami Marlins.

Miami is 55-55 in the 2025 season and on the outside of the playoff picture in the National League, but it does have some intriguing young pieces that could put the team into playoff contention in the near future. 

The Marlins also held on to former Cy Young award winner Sandy Alcantara through the trade deadline, and the righty will start on Monday night. It’s been a rough season for Alcantara (6.36 ERA) as he works his way back from Tommy John surgery.

However, the best betting sites have the Marlins set as favorites in this matchup with Jason Alexander (7.36 ERA) on the mound for Houston.

Here’s a breakdown of the odds, my favorite prop bet and a prediction for this series opener. 

Astros vs. Marlins Odds, Run Line and Total

Odds via DraftKings Sportsbook

Run Line

• Astros -1.5 (+153)
• Marlins +1.5 (-188)

Moneyline

• Astros: -102
• Marlins: -119

Total

• 8.5 (Over -106/Under -115)

Astros vs. Marlins Probable Pitchers

• Houston: Jason Alexander (1-1, 7.36 ERA)
• Miami: Sandy Alcantara (6-9, 6.36 ERA)

Astros vs. Marlins How to Watch

• Date: Monday, Aug. 4
• Time: 6:40 p.m. EST
• Venue: loanDepot park
• How to Watch (TV): FDSFL, SCHN
• Astros record: 62-50
• Marlins record: 55-55

Astros vs. Marlins Best MLB Prop Bets

Marlins Best MLB Prop Bet

• Kyle Stowers to Hit a Home Run (+320)

Earlier today, I shared in SI Betting’s best home run picks – Daily Dinger – why Kyle Stowers will stay hot against Houston: 

Miami Marlins All-Star Kyle Stowers dominated the Yankees over the weekend, hitting a pair of home runs to push his total to 25 in the 2025 season. 

Overall, Stowers is hitting .296 with a .947 OPS, but against right-handed pitching he’s been even better. Stowers is hitting .300 against righties with a 1.001 OPS, and 24 of his 25 home runs have come against them.

In fact, his first homer of the season against a lefty was on Sunday against New York.

On Monday night, Stowers will take on Jason Alexander and the Houston Astros, and Alexander has struggled so far in 2025. 

The righty has appeared in eight games, posting a 7.36 ERA while allowing five homers. In each of his last two starts, he’s been taken deep. 

It’s hard to find a better matchup for Stowers, who is hitting .347 with 10 home runs over the last 30 days. 

Astros vs. Marlins Prediction and Pick

It’s been a rough season for Alcantara, but he may be turning things around late in the 2025 campaign. 

The righty has allowed just seven hits and one unearned run over his last two starts (12.0 innings of work), and he’s lowered his ERA from 8.47 at the end of May to 6.36 at the end of July. It’s not great, but it’s progress.

Meanwhile, Houston is struggling right now, dropping eight of its last 10 games despite making some all-in moves at the deadline.

The Marlins swept the Yankees over the weekend to push their winning streak to five, and their offense ranks in the top half of MLB in OPS over the last week. For a team that has struggled to score (20th in runs this season) this could be a step in the right direction.

I don’t trust Alexander (7.36 ERA, 1.83 WHIP) to lead Houston to a win in this matchup, so I’ll bet on Alcantara staying hot at home. 

Pick: Marlins Moneyline (-119 at DraftKings)

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Odds refresh periodically and are subject to change.

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