3 observations as 1st-place Mariners hit stretch run

Sep 14, 2025, 6:56 PM

Seattle Sports

The Seattle Mariners are on absolute tear at an ideal point.

With just two weeks and 12 games left in the regular season, the Mariners are riding a season-best nine-game winning streak. They’re alone atop the American League West for the first time in over three months. And just about everything seems to be clicking all at once, something this club has been waiting on for quite some time.

More history: Cal Raleigh ties Mantle for switch-hitter HR record

Here are three observations as the club prepares for its final road trip of the season, which includes a pivotal three-game set with the Houston Astros.

Polanco’s decision a key of season

At this point last season, it seemed as if Jorge Polanco’s first year in a Mariners uniform would be his last. The veteran switch-hitter struggled throughout 2024, posting career worsts in batting average (.213), OPS (.651) and strikeout rate (29.2%).

So it was a bit surprising when the Mariners re-signed Polanco to a one-year deal in early February. Perhaps even more surprising is Polanco reportedly chose to return to Seattle and play half his games at the toughest park to hit in the league when he was also receiving intertest from the Astros.

Well, the Mariners and Polanco have to be pretty happy about the ways things turned out, because the 32 year old is having one of the best seasons of his career while being a key cog in the middle of the lineup.

Polanco is slashing .267/.328/.497 with 28 doubles, 24 home runs and 72 RBIs this season. He doubled three times during Sunday’s win over the Angels while tying Jim Presley’s franchise record with his seventh straight game with a double. And his 129 wRC+ entering Sunday was the best mark of his career and trailed only Cal Raleigh among M’s regulars.

It’s hard to imagine where this team would be without Polanco. It would be even harder to imagine them in first place if he had ended up going to Houston.

Rotation rounding into form at right time

The expectation coming into this season is the Mariners would go as far as their pitching staff would take them. But with injuries and inconsistencies plaguing the starting rotation, the offense has ended up being just as big (if not bigger) a part of the team’s success.

The club hasn’t reached the level of pitching dominance it displayed a year ago, but the starting rotation appears to be rounding into form just in time for the final push.

George Kirby delivered a big bounce-back start Sunday, matching a career high with 14 strikeouts. Luis Castillo is coming off two strong outings following a rough stretch. Bryce Miller is looking better than he has all season since returning from his second stint on the injured list.nLogan Gilbert, while not going as consistently deep into games, is striking out batters at a rate well above where he’s been in the past. And Bryan Woo continues to be a model of consistency while turning in quality start after quality start.

Add in the fact that the bullpen has given up only single earned run over 38 innings during the win streak, and this Mariners pitching staff as a whole is looking closer to what it was a year ago than it has all season.

The caveat is that Seattle hasn’t faced the toughest competition of late with consecutive series against Braves, Cardinals and Angels squads that are all below .500. But we should have a better idea of how much progress the pitching has made after the upcoming homestand, especially from the results of the three games in Houston.

Road trip can change everything

The Mariners’ hot stretch is quite a turnaround from what had transpired beforehand – a stretch of 15 losses in 21 games. So, things could flip back the other way in quite a hurry. That rings especially true for the upcoming road trip.

The trip begins with three games against a Kansas City Royals squad that has started to slip, but given the M’s some troubles and bizarre games at Kauffman Stadium in recent years. Those include surrendering a nine-run lead to the well-below-.500 Royals in September of 2022 and giving up an eight-run lead in what proved to be a costly June loss last season.

The series in Houston afterwards figures to go a long way in deciding who wins the division. The winner of the three-game showdown earns the head-to-head tiebreaker, which is essentially a bonus notch in the win column for the division race. The Mariners went 1-3 in their trip to Houston earlier this year, but Daikin Park hasn’t been nearly as tough a venue recently as it has been in the past, with the M’s taking four of their past five series there.