Mariners vs. Marlins Prediction, Odds, Probable Pitchers, Prop Bets for Thursday, July 9

The Miami Marlins are one win away from a sweep of the Seattle Mariners on Thursday night, but they are set as home underdogs with right-hander Janson Junk on the mound.

Junk (4.80 ERA) is making his first start since late May, and Miami is 5-6 so far in the 2026 season with him on the bump.

Seattle enters this game in first place in the shaky AL West division, but it’s just 5-5 in its last 10 games. Bryce Miller (1.71 ERA) has been lights out for the Mariners this season, and he’ll look to salvage the final game of this series.

So, how should we bet on this interleague clash?

Here’s a look at the odds, a player prop to bet and my prediction for Thursday night’s series finale.

Mariners vs. Marlins Odds, Run Line and Total

Odds via DraftKings Sportsbook

Run Line

Mariners -1.5 (+133)
Marlins +1.5 (-161)

Moneyline

Mariners: -127
Marlins: +105

Total

8 (Over -109/Under -110)

Mariners vs. Marlins Probable Pitchers

Seattle: Bryce Miller (4-2, 1.71 ERA)
Miami: Janson Junk (3-5, 4.80 ERA)

Mariners vs. Marlins How to Watch

Date: Thursday, July 9
Time: 6:40 p.m. EST
Venue: loanDepot park
How to Watch (TV): Mariners.TV/Marlins.TV
Mariners record: 47-46
Marlins record: 51-42

Mariners vs. Marlins Best MLB Prop Bets

Mariners Best MLB Prop Bet

Bryce Miller OVER 5.5 Strikeouts (-151)

In today’s MLB best bets column – Walk-Off Wagers – I explained why Miller is undervalued in the strikeout market against Miami:

Seattle Mariners starter Bryce Miller has put together a strong 2026 season, posting a 1.71 ERA across nine outings.

He shut down the Los Angeles Angels in his last appearance, allowing no runs, two hits and striking out eight across seven innings of work.

Miller now has six or more K’s in six straight starts and seven of his nine appearances in 2026. So, why not take him to clear this line again on Thursday?

Miller is facing a Miami Marlins team that is ninth in MLB in strikeouts per game, but I think this line is way too low for the Mariners right-hander. In 2026, Miller ranks in the 98th percentile in chase percentage, the 78th percentile in whiff percentage and the 96th percentile in strikeout percentage.

He’s also worked into the sixth inning in five of his last six starts. I think we’re getting quite the discount on this strikeout prop on Thursday.

Mariners vs. Marlins Prediction and Pick

Miller has simply been too good this season to pass up at this price, as he ranks in the 99th percentile in expected ERA and the 96th percentile in expected BAA.

Junk, on the other hand, is in the 54th percentile in expected ERA and has struggled to generate swings and misses in 2026, ranking in the fourth percentile in whiff percentage.

Seattle has not been great on the road (20-26) and that has shown in this series with the Mariners scoring just five runs across two games. However, Miller hasn’t allowed more than three runs in any of his nine outings, and he should be able to outduel Junk in this matchup.

I don’t mind taking Seattle in the first five innings on the moneyline as well, especially since the Marlins have one of the best bullpens in MLB.

Pick: Mariners Moneyline (-127 at DraftKings)

Odds refresh periodically and are subject to change.

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