Rangers vs Mariners Odds, Picks, & Predictions: Expect a Pitcher's Duel in the Emerald City

With ace Luis Castillo taking the hill, Seattle will look to keep its playoff hopes alive when it faces Texas on Saturday night in the Emerald City. Read on as we break down this pivotal AL West matchup in our Rangers vs. Mariners betting picks.

Last Updated: Sep 30, 2023 3:27 PM ET Read Time: 4 min
Luis Castillo Seattle Mariners MLB
Photo By - USA TODAY Sports

The Seattle Mariners are just a game back of the Astros for the final wild-card spot in the American League and will look to move one step closer to the postseason with a win over the Texas Rangers on Saturday night.

Will Luis Castillo rebound after a brutal outing against Houston to keep Seattle’s playoff hopes alive? Let’s break down Rangers vs. Mariners in our MLB picks and predictions.

Rangers vs Mariners odds

Rangers vs Mariners predictions

Don’t let this matchup here scare you. There’s at least some reason to believe that Andrew Heaney can lead Texas Rangers to victory on Saturday night.

The Heaney fastball has been playing up much better these days, and overall his arsenal has produced a declining expected batting average over the last three months. His mark of .243 in July constituted as average, which was a step in the right direction, and he followed that by boasting a .235 xBA in August and a .212 xBA here in September.

While Heaney's walks have begun to climb, this month is an outlier and his strikeout numbers remain the same. I don’t think Heaney has been all that bad, and we know the Seattle Mariners have been very mediocre offensively for the majority of the season.

On the other side of the coin, the Rangers are beginning to tense up with the playoffs around the corner, scoring just two runs over the last two nights. Considering Texas has struggled against the four-seam fastball, the bats will have their hands full against Luis Castillo on Saturday night.

Castillo owns a 2.81 ERA at home compared to a 3.62 ERA on the road, taking full advantage of a pitcher’s park in Seattle as a pitcher who gets a lot of outs courtesy of his outfield. The Rangers are a flyball team, and that should play right into the righty’s hands here as we witness a pitcher’s duel.

My best bet: Under 7.5 (-118 at DraftKings)

Not intended for use in MA.
Affiliate Disclosure: Covers may receive advertising commissions for visits to a sportsbook or betting site

Rangers vs Mariners same-game parlay

Under 7.5 (-120)

Luis Castillo 6+ strikeouts (-390)

Julio Rodriguez 2+ total bases (+100)

One thing we have to keep in mind is that Heaney won’t be going 4-7 innings like a normal starting pitcher. He's been much more effective out of the bullpen in short stints, so we’ll probably see him for two or three frames.

That shouldn't worry bettors, as left-hander Martin Perez is lined up to pitch after him. Although the Mariners have struggled against southpaws all year. one guy who hasn’t is Julio Rodriguez.

The man whom I’ve nicknamed “K-Rod” has been a huge disappointment during this critical stretch for the Mariners, going 1-for-17 in his last five games with a solo homer and eight strikeouts. One thing we do know, however, is he mashes lefties with a 137 wRC+ in the split.

I feel like that’s attainable, despite how poorly he’s played, and I definitely expect Castillo to rack up six strikeouts. Not only did he do so the last time he faced the Rangers, but the Mariners' right-hander has struck out exactly eight in each of his last four outings.

The Rangers have been punched out over 22% of the time over the last two weeks and could be in for a long night against Seattle's ace.

Learn how to bet a same-game parlay with these helpful tips and strategies.

Best MLB bonuses

DraftKings All Users
Profit boost (up to 100%) on one SGP daily! Claim Now

Caesars New Users
Get up to $1,000 in bonus bets if your first bet doesn't win! Claim Now

Eligible USA locations only. Also, see our full list of best sportsbook promotions for 2023.
21+. Gambling Problem? Call 1-800-GAMBLER

Rangers vs Mariners moneyline and Over/Under analysis

After fading the Mariners for most of the last week, I will concede that this is a matchup that favors Seattle. Although the M's offense has faced challenges with left-handed pitchers this season, they should have a relatively straightforward time against a subpar arm like Perez. Additionally, it's likely they won't have to contend with Heaney for an extended period, even if he's pitching effectively.

Although it does feel like this Texas offense is ready to blow, the Rangers have not hit the fastball well and are in for a tough night at the plate against Castillo. With home-field advantage and the Mariners desperately in need of another win to keep their playoff hopes alive, they should be able to squeak this one out.

Ultimately, I’d lean toward taking the Mariners and Under here.

Trend to know

The Mariners have cashed the moneyline in 49 of their last 80 games (+9.20 Units / 8% ROI). Find more MLB betting trends for Rangers vs. Mariners

Kentucky: Mobile sports betting is live!

Check out the best Kentucky sportsbook promos, with a number of odds boosts and offers available!

Kentucky sports betting launched online wagering on September 28 — review our list of the best Kentucky sports betting apps for making your first online bets in the Bluegrass State!

21+ and present in KY. Gambling Problem? Call 1-800-GAMBLER

Rangers vs Mariners game info

Location: T-Mobile Park, Seattle, WA
Date: Saturday, September 30, 2023
First pitch: 7:15 p.m. ET

Starting pitchers

Andrew Heaney (10-6, 4.28 ERA): The veteran lefty has found new life pitching in shorter spurts, totaling five scoreless innings in all of his last four appearances. He’s allowed just one hit over that span, walking three and striking out five.

Luis Castillo (14-8, 3.20 ERA):  The flamethrower didn’t have his best stuff last time out against the Astros, coughing up five runs over six frames. He still struck out eight for a fourth straight start and maintains a 4.20 ERA in September.

Latest injuries


Google News
Stay updated with the latest picks, odds, and news! Tap the star to add us to your favorites on Google News to never miss a story.

Pages related to this topic

Popular Content

Legal Canadian sports betting

Best Canadian betting sites Ontario sports betting
Covers 25 Years Logo Established in 1995,
Covers is the world
leader in sports
betting information.
Covers is verified safe by: Evalon Logo GPWA Logo GDPR Logo GeoTrust Logo Evalon Logo