Astros vs. Tigers Prediction, Odds, Probable Pitchers and Prop Bets for Monday, Aug. 18

The Tigers are favored at home on Monday, but are they the best bet?

Detroit Tigers left fielder Riley Greene is a solid prop target on Monday night. / Lon Horwedel-Imagn Images

Both the Houston Astros and Detroit Tigers are atop their divisions entering Monday night’s action, but the Tigers have a much bigger cushion in the AL Central standings than the Astros do in the AL West. 

Houston will have righty Spencer Arrighetti on the mound for the fifth time this season, as he’ll look to rebound from a rough start (6.38 ERA) to his 2025.

Veteran Jack Flaherty will get the ball for Detroit, and he’s struggled a bit this season, posting a 4.76 ERA while leading the Tigers to just a 7-17 record in his outings.

Despite that, the best betting sites have the Tigers set as favorites at home, where they are 39-24 so far in 2025.

Let’s dive into the odds, players to bet on in the prop market, and my prediction for Monday’s matchup between these playoff contenders.  

Astros vs. Tigers Odds, Run Line and Total

Odds via DraftKings Sportsbook

Run Line

• Astros +1.5 (-175)
• Tigers -1.5 (+143)

Moneyline

• Astros: +118
• Tigers: -145

Total

• 8.5 (Over -105/Under -115)

Astros vs. Tigers Probable Pitchers

• Houston: Spencer Arrighetti (1-3, 6.38 ERA)
• Detroit: Jack Flaherty (6-12, 4.76 ERA)

Astros vs. Tigers How to Watch

• Date: Monday, Aug. 18
• Time: 6:40 p.m. EST
• Venue: Comerica Park
• How to Watch (TV): MLB Network, FDSDET, SCHN
• Astros record: 69-55
• Tigers record: 73-53

Astros vs. Tigers Best MLB Prop Bets

Tigers Best MLB Prop Bet

• Riley Greene to Hit a Home Run (+425)

Earlier today, I shared in SI Betting’s best home run picks – Daily Dinger – why Greene has a prime matchup to go deep on Monday: 

Detroit Tigers outfielder Riley Greene has struggled a bit since the All-Star break, hitting just .204 over his last 24 games, but I love this matchup for him on Monday night.

Greene is taking on the Houston Astros and starting pitcher Spencer Arrighetti, who enters this start with a 6.38 ERA and two homers allowed in four outings in 2025. 

In his career against Arrighetti, Greene is 2-for-2 with two homers and four runs batted in. So, he’s homered every time he’s faced the Astros starter.

While he may not homer every time against Arrighetti, I do like him at this price on Monday, especially since Greene is hitting .289 with 26 of his 28 home runs against right-handed pitching this season. 

Astros vs. Tigers Prediction and Pick

Even with Detroit favored against Arrighetti and Houston, I can’t bet on the Tigers to win with Flaherty on the mound.

As I mentioned earlier, Detroit is just 7-17 in its 24 outings this season, and Flaherty has a 4.14 expected ERA, which backs up his overall struggles (4.76 ERA) this season.

The veteran right-hander has allowed 12 runs in his three August starts, and he’s given up four or more runs in seven outings in 2025. 

As for Arrighetti, he only allowed two runs in his last outing, but he’s walked 11 batters and has a 1.47 WHIP in his four starts in 2025. The Astros have combined for 10 or more runs in each of the righty’s last two outings.

This season, Detroit is eighth in runs scored and has one of the best OVER records (65-55-6) in MLB.

Given the pitching matchup, I think this could be a high-scoring series opener. 

Pick: OVER 8.5 (-105 at DraftKings)

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Odds refresh periodically and are subject to change.

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