Mariners pull up Shawn Armstrong, drop Nick Rumbelow to AA-Arkansas

As Mariners fans wait for Edwin Díaz’s haircut choice of Scott Servais to conclude, Seattle shuffled a pair of winter acquisitions in the bullpen.

Shawn Armstrong (pictured above, sort of) was acquired from Cleveland with some of the leftover international signing money Seattle wound up with after their failed pursuit of Shohei Ohtani. He was slipped through waivers prior to the season’s outset and has spent the entirety of the season as the Rainiers’ closer/bane of the PCL’s existence. Armstrong is 6th in the PCL in K% for pitchers with at least 30.0 IP at a cool 35.7% strikeout rate, and his repertoire has always been catered towards K’s. As Marc W at USS Mariner noted when Armstrong first was acquired, there’s a certain Nick Vincent quality to Armstrong’s repertoire, with an extreme fly-ball profile and a high-spin four-seam/cutter as the majority of what he delivers.

When it’s located well, it can be quite effective.

Sometimes overlooked high-K 27-year-old pitchers in AAA become useful back-end relievers like Blake Parker. Just as often, it’s increasingly challenging to make that leap without electric stuff. While Armstrong’s stuff isn’t as amusingly soft-pedaling as Vincent’s, a fastball at 92-94 and a cutter in the 88-91 range is the difference between a middle relief profile and Álex Colomé’s high-leverage role with his 94-97/90-93 fastball/cutter.

Armstrong replaces the struggling Nick Rumbelow, who will ship off to AA-Arkansas in an attempt to get right in a way he has failed to since a nerve injury sidelined him for months to start this year. Rumbelow’s command has been his undoing, as his pitches are still eliciting bad swings out of the zone at their best, but leaving pitches down the middle too often has held back one of the more promising talents in the system from a high-leverage role. While it’s pure conjecture, with James Pazos working his mechanics with a meticulously crafted plan in Tacoma, it’s possible Rumbelow is being sent to Arkansas with a similar mandate for highly-regarded pitching coach Ethan Katz.

Seattle’s 40-man roster now sits at 39. Update: This actually puts the 40-man roster at 40, however with Juan Nicasio out for the year, he can at any time be moved to the 60-day DL. Additionally, it seems as though Max Povse is eligible for the 60-day DL unfortunately, so Seattle likely has a couple roster spots to work with as they head towards September.