SEATTLE -- It was the worst possible time for the Mariners’ ace to turn in his worst possible start in 2023, and after Luis Castillo was tagged for four runs while failing to make it out of the third inning, a 6-1 loss to Texas on Saturday had Seattle on the cusp of elimination.

The Mariners’ fate was left in the hands of the Astros, who with a win at Arizona eliminated Seattle from postseason contention.

“We just didn't get it done,” catcher Cal Raleigh said. “At the end of the day, it falls on us -- nobody except us. And it's something we're going to live with this whole offseason.”

“La Piedra” could not have looked further from himself as he labored into eight full counts, nearly all of which proved fateful. In those sequences, he walked four (of five total), surrendered an RBI single to Nathaniel Lowe, struck out one and induced a flyout. His final free pass, to No. 9 hitter and rookie Evan Carter, ended his day with two outs in the third after a whopping 86 pitches, including 42 in his final frame.

It was the most confounding result given the stakes of the game and that Castillo has a penchant for thriving at this time of year. He cruised through the first inning with two strikeouts while dialing his fastball well above his season average, to 98.3 mph. Then in the second, he worked around two walks with an inning-ending flyout to Carter.

That at-bat dropped Texas to 0-for-21 with runners in scoring position dating back to Tuesday at Anaheim. Yet that line was always going to be an outlier for one of MLB’s best offenses, and it proved to be true in the third. Castillo generated two outs after walking the leadoff man, Marcus Semien, but the floodgates opened from there, as each of the next six batters reached to end his day.

“Just a lot of non-competitive pitches,” said Raleigh, who was behind the plate. “He wasn't putting them away. He didn't really hit his spots in those two-strike counts, and hats off to them. They had some good at-bats and grinded out some at-bats and fought some pitches off. But he usually gets it done, usually with two strikes, and today he just couldn't get it done.”

Castillo struggled to land all his pitches. The four-seamer had too many arm-side misses to lefties, while the slider and changeup steered way too far off the plate. Castillo threw 34 pitches in two-strike counts but only three generated whiffs.

“We weren't able to control the zone,” Castillo said through an interpreter. “We were down in the count a lot, and I think that's why we lost the game.”

The Mariners fell to 20-39 in games in which their starter pitched fewer than five innings, a mark that Castillo had cleared in each of his 32 outings entering play. It’d been a Cy Young Award-caliber season for Seattle’s No. 1 starter before this homestand, but his final two outings have soured his bid. Including Monday’s loss to Houston, Castillo surrendered nine earned runs on 13 hits and six walks, for a 2.19 WHIP and 9.35 ERA.

Add in that Texas deployed a bullpen game from a relief corps that in the second half has been worth minus-0.5 wins above replacement by FanGraphs (third worst in MLB), and on paper, Saturday looked like the Mariners’ most winnable game on this 10-game sprint to the finish.

But it was anything but, as Seattle’s offense stalled against lefty Andrew Heaney and squandered its best chance to get back in the game after loading the bases with one out in the fifth. Josh Sborz, who replaced Heaney, got Julio Rodríguez to pop out and Eugenio Suárez to ground out. Suárez homered in his next at-bat, in the eighth, to avoid what would’ve been Seattle’s ninth shutout and second since last Saturday in Arlington.

Beyond Castillo, Rodríguez’s struggles during this final stretch have been perhaps more glaring -- and costly. His lunging swing on a changeup way off the plate for strike three in the eighth was a microcosm of his night. The Mariners’ offense runs through its best player, and Rodríguez went 0-for-4 on Saturday to drop his slash line since last Friday’s series opener at Texas to .121/.205/.273.

“I take that on myself,” Rodriguez said. “I prepare and everything. It just didn't happen. It didn't happen for me. It's not the way that I wanted it.”