David Aardsma. Brandon League. Nick Vincent.
No, you’re not having another one of your worrying dreams about a Mariners bullpen comprised of several decent-though-not-star-caliber players. It’s merely a short list of solid trade acquisitions the Mariners have made for their high-leverage relief work. Despite a more suspect series of dalliances in the free agent market for bullpen help in recent years, trades have often yielded, well, relief. The past has little bearing on Montero’s future, but as a veteran option in what was a dismal bullpen group a year ago, and dealt away its most promising performers from 2020, the former Texas Rangers stopper is in line to be the Seattle Mariners closer.
Montero will lead a group of harder throwing relievers than Seattle has had recently. Even with Edwin Diaz incinerating opponents in the ninth inning of 2016-2018, the M’s have ranked 23rd, 28th, 13th, 18th, and 27th in fastball velocity (per FanGraphs) stretching back from 2020 thru 2016. Several of the likely M’s bullpen arms average mid-90s heat, with Montero comfortably near the top at nearly 96 mph.
Montero’s four-seam and sinker make up the majority of his offerings in total, and they can be impressive. The four-seam has decent shape, with a nice touch of rise, but its main separator is its speed. At the moment, it’s his best out pitch against right-handed hitters, which is a bit of a problem that we’ll get to in a moment.
The sinker is more aptly simply a two-seamer, as it lacks much distinction in sinking movement. It scarcely drops velocity from the four-seamer to its credit, and is mostly used against left-handed hitters, which may help its traits play up, as the pitch is otherwise a bit suspect. Still, he tends to locate the pitch well and, along with his changeup, draws swings that have lower likelihood of dangerous outcomes.
Unfortunately, the changeup and sinker don’t have much differentiation at the moment, which undercuts the efficacy of both. The changeup has decent shape at times, but at 89-90 mph it needs either sharper bite or a drop in velo to create more swings like this:
Still, like the sinker, the changeup is almost exclusively a lefty-felling weapon, and it works alright at that, inducing whiffs at a well above-average rate. Like many righties, he walks lefties at a higher rate than righties, but he’s avoided any serious troubles with those diving offerings. Righties have obviously struggled to handle his heater, but Montero stands out as a fairly strong reliever without a particularly good breaking ball. At present he offers a slider that most resembles a cutter, with little sink and mostly horizontal break.
All of this makes for a curious high-leverage hurler. In 46.2 innings over 2019 and 2020, Montero had a 3.09/3.78 ERA/FIP and a shiny 28.6% strikeout rate to just a 5.9% walk rate. The M’s bullpen last year didn’t so much Control The Zone as they assailed it like a barfly aims at a dartboard 15 minutes before last call. After leading the league in walks per nine innings and giving free passes a grisly 12.4% of the time last year as a unit, the bullpen could do worse than to be anchored by an uncommonly accurate fireballer. If the M’s can build on Montero’s accuracy with a sharper breaking ball of some sort, he’ll be right at home locking up late leads.