The Philadelphia Phillies host the Seattle Mariners in the final matchup of this three-game series at Citizens Bank Park. MLB odds list Philadelphia as a -140 favorite, while the total sits at 8.5.
My Mariners vs. Phillies predictions expect a low-scoring affair this afternoon.
Read on for my MLB picks for Wednesday, August 20.
Mariners vs Phillies prediction
Mariners vs Phillies best bet: Under 8.5 (+100)
Southpaw Jesus Luzardo takes the mound for the Philadelphia Phillies, and he should serve as a good candidate to back. Despite a rocky start to the season, Luzardo’s underlying metrics suggest positive regression is likely to occur the rest of the way.
Entering this matchup, he ranks in the top half of the league in xERA, xBA, barrel rate, and hard-hit rate. This expected positive regression has started to come to fruition recently, given Luzardo has allowed three or fewer runs in each of his past four starts.
Over that stretch, the lefty is 3-1 with a 2.52 ERA and 0.92 WHIP.
Meanwhile, the Seattle Mariners hand the ball to RHP Luis Castillo. Through 25 starts this season, Castillo is 8-6 with a 3.48 ERA and 1.22 WHIP. He also boasts a 2.75 ERA and 0.86 WHIP through three starts against the Phillies.
Castillo’s analytics this season are slightly concerning, but he just has to avoid getting shelled for this Under to stay alive.
Mariners vs Phillies same-game parlay (SGP)
Castillo has recorded five or more strikeouts in six of his past eight starts, while Luzardo has posted seven or more strikeouts in seven of his past 10 outings.
Furthermore, Luzardo ranks in the top quarter of the league in chase rate, whiff rate, and strikeout rate.
Mariners vs Phillies odds
- Moneyline: Seattle +118 | Philadelphia -141
- Run line: Seattle +1.5 (-189) | Philadelphia -1.5 (+158)
- Over/Under: Over 8.5 (-120) | Under 8.5 (+100)
Mariners vs Phillies trend
There have been five total runs scored in each of Luzardo’s past two starts. Find more MLB betting trends for Mariners vs. Phillies.
How to watch Mariners vs Phillies and game info
| Location | Citizens Bank Park, Philadelphia, PA |
| Date | Wednesday, August 25, 2025 |
| First pitch | 1:10 p.m. ET |
| TV | RSNW, NBCSP |
| Mariners starting pitcher | Luis Castillo 8-6, 3.48 ERA) |
| Phillies starting pitcher | Jesus Luzardo (11-6, 4.21 ERA) |
Mariners vs Phillies latest injuries
Mariners vs Phillies weather
Odds are correct at the time of publishing and are subject to change.
Not intended for use in MA.
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