Mariners 2025 Schedule: Important dates, key series, SoS, more

The Seattle Mariners are less than two weeks away from hosting the Athletics in their 2025 opener at T-Mobile Park. And rest assured, a lot will happen between then and the end of their regular season.

If you're looking to learn more about what's ahead for the Mariners, you've come to the right place.

We're going to break down all the need-to-know information concerning Seattle's '25 schedule, including key dates on the calendar, the Mariners' overall strength of schedule, when they will face their top AL West rivals, and both soft and hard sections of their 162-game slate.

For a glimpse at the Mariners' full schedule, click here.

Important Dates

• March 27: Opener vs. Athletics
• May 16-18: Rivalry Weekend vs. San Diego Padres
• July 12: Futures Game
• July 13: 1st round of MLB Draft
• July 14-17: MLB All-Star break
• July 31: MLB trade deadline
• September 1: Rosters expand from 26 to 28 players
• September 28: Last game vs. Los Angeles Dodgers

The Mariners' 2025 schedule will unfold over 185 days, thus giving them only 23 off days sprinkled throughout the 162-game grind.

Four of those off days will come during the All-Star break, wherein the Home Run Derby will go down Monday, July 14 followed by the All-Star Game on Tuesday, July 15. The Mariners will hope to be well-represented for both, which will be held at Truist Park in Atlanta.

Where the Mariners will almost certainly be well-represented is in the Futures Game. The club's collection of prospects is considered by some to be the best of Major League Baseball.

The draft will be a hugely important event for the Mariners, as their No. 3 pick is the franchise's highest in over a decade. The date for the trade deadline otherwise just dropped this week, and it's not too soon for the Mariners to be thinking about possible upgrades.

Strength of Schedule

According to FanGraphs, the strength of the Mariners' 2025 schedule is rated at .498. That denotes a relatively easy slate with more soft targets than hard targets.

It is important to note that this is based on forward-looking projections, and even those tell a slightly different story than the one summarized in the number above. Out of the Mariners' 162 games in 2025, only 59 are against teams that project to finish below .500.

However, also important to note is that the Mariners project for a .522 winning percentage. That's 85-win territory, which sounds unimpressive unless you take the nature of these projections into account. They are on the conservative side, and so much so that 135 of the Mariners' games will be against teams that project for a lower winning percentage.

Key Series Against AL West Rivals

Here is when the Mariners will face their AL West rivals in 2025, with home series in bold font:

• Athletics: March 27-30, May 5-7, July 28-30, August 22-24
• Houston Astros: April 7-9, May 22-25, July 18-20, September 19-21
• Los Angeles Angels: April 29-30, June 6-8, July 24-27, September 11-14
• Texas Rangers: April 11-13, May 2-4, June 27-29, July 31-August 3

According to FanGraphs, the Astros and Rangers loom as the only other playoff contenders in the AL West. They have chances of 53.9 and 56.0 percent of making the postseason, respectively, compared to 56.5 for the Mariners.

Playing well against Houston and Texas was not an issue for the Mariners in 2024, as they went 8-5 against the former and 10-3 against the latter. If they can repeat that, it's the rest of their schedule that they'll need to take care of in order to return to October for the first time since 2022.

Hard and Soft Stretches

Regarding which parts of the schedule the Mariners should be mindful of, keep an eye on these:

• Light Stretch: April 11-May 11
• Hard Stretch: August 12-September 7

In the light stretch, the Mariners will play 26 straight games against teams that did not quality for the 2024 playoffs. There are some tough customers in there, including the Rangers and Boston Red Sox. But on the whole, it's an uncommon soft spot the Mariners will need to exploit.

On the flip-side, that hard stretch will see the Mariners play 18 out of 24 games against playoff teams from last year. All but one of those teams projects for a winning record again in 2025, and that one exception is a Cleveland Guardians squad that has a tendency to surprise.

Whatever the case, performing against fellow contenders is where the Mariners must be better in 2025. They went 40-46 against teams with winning records last season, which certainly contributed to them falling one game short of the playoffs for the second time in as many years.