The Seattle Mariners host the Cleveland Guardians on June 13, 2025. First pitch from T-Mobile Park is scheduled for 10:10 p.m. EDT; the game will be broadcast on ROOT Sports NW.
The Mariners have dropped three straight, falling below .500 for the season (33-34), and now begin this series against the Guardians (35-32). Gavin Williams will pitch for Cleveland and face Seattle's Luis Castillo.
Find my MLB betting preview and Guardians vs Mariners prediction below, as well as probable pitchers, betting trends, injury reports and more.
My Guardians vs Mariners Prediction
- Guardians vs Mariners picks: Cleveland Guardians F5 ML
My Guardians vs Mariners best bet is on the Guardians' first five innings moneyline. Make sure to find the best odds by checking our live MLB odds page.
Guardians vs Mariners Odds
| Guardians Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
-1.5 +165 | 7 -120o / 100u | -110 |
| Mariners Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
+1.5 -200 | 7 -120o / 100u | -110 |
Guardians vs Mariners Projected Starting Pitchers
| RHP Gavin Williams (CLE) | Stat | RHP Luis Castillo (SEA) |
|---|---|---|
| 5-3 | W-L | 4-4 |
| 0.5 | fWAR (FanGraphs) | 1.2 |
| 3.86/4.40 | ERA /xERA | 3.31/4.67 |
| 4.39/3.95 | FIP / xFIP | 3.66/4.26 |
| 1.42 | WHIP | 1.30 |
| 12.4 | K-BB% | 11.9 |
| 42.0 | GB% | 40.5 |
| 100 | Stuff+ | 98 |
| 92 | Location+ | 104 |
John Feltman’s Guardians vs Mariners Preview
Cleveland Guardians Betting Preview: Solid Matchup for the Offense
If you had looked at this matchup on paper two seasons ago, many of you reading this would have concluded the Guardians were in trouble. However, the truth of the matter is Castillo is no longer the pitcher he once was.
Tonight, I like the matchup for Cleveland. Lifetime against Castillo, the team is batting .275 with 6 homers over 80 at-bats.
Cleveland is also stronger against right-handed pitching. The Guardians are batting .238 versus righties, which isn’t ideal, but it is at least a more favorable matchup for them.
What I like tonight for them is that there is a matchup on the mound.
Gavin Williams is off to a decent start in 2025, entering tonight with a 3.86 ERA. What I take away from Williams’s metrics is he's generating a lot of whiffs and sports a 25% strikeout rate.
He also keeps the ball on the ground and limits the hard contact, although his walk rate remains exceptionally high, resulting in a WHIP of 1.42.
Williams has faced a few Seattle bats in the past, and they are a combined 0-13. Given Williams and the Guardians' matchup offensively, it’s hard not to like them at their current price.
Seattle Mariners Betting Preview: Castillo's Decline
Luis Castillo appears to be declining in his career, and his metrics support that assessment. He enters tonight with a respectable 3.31 ERA and 1.30 WHIP, but many red flags suggest he is due for significant regression.
Castillo's xERA is 4.67, which is 1.36 higher than his actual ERA. He also has a .276 xBA and mediocre chase and whiff rates.
Castillo is getting stuck and not keeping the ball on the ground as much. All these suggest hitters are consistently squaring the ball up against him, and he is not striking out bats as he used to.
At 32 years old, it’s time to ponder if Castillo’s name is why the market currently lists the Mariners as short home favorites.
I also don’t like Seattle's offensive matchup tonight. Williams is having a strong season, and the Mariners' limited at-bats against him have not been successful. The Mariners bat .241 against right-handed pitching, but they are in the middle of the pack in runs scored per game.
Their offense is consistently far too untrustworthy for me to back them against Williams tonight, especially with Castillo's looming regression on the horizon.
Guardians vs Mariners Prediction, Betting Analysis
I like the Guardians in the first five innings tonight. Williams has an intense matchup against the streaky Seattle offense, and I will be looking to fade Castillo for the rest of the year.
In my opinion, the market is still overpricing him based on name brand and not accounting for his underlying metrics.
I expect the Guardians to score a couple off of Castillo early, and Williams should cruise in the early going
Pick: Cleveland Guardians F5 ML
Guardians vs Mariners Betting Trends
Guardians vs Mariners Weather
