In a sense, Brandon Brennan is already a success story for the Mariners. Few Rule-5 Draft picks stick with their teams long term. The solid numbers he put up in 2019 assured him a spot in the 2020 bullpen, with a shot at high-leverage work among an injury-prone and unproven assortment of arms. Sadly, Brennan spent most of this past season out of commission between two different injured list stints. The 2021 Mariners have already added a pair of relievers and should add more, but for now Brennan has a shot at opening the season in the M’s middle relief role as a groundball specialist. It’s imperative he rediscover his knack for inducing whiffs and wormburners he had in 2019, and it seems like that all starts with health.
In 2019, Brennan’s changeup was, without hyperbole, one of the best pitches in baseball. Over half the times hitters took their bats off their shoulder and journeyed after his changeup in hopes of contact they returned home empty-handed. Hitters couldn’t handle it in the strike zone, they struggled to square him up when working against his 93-96 mph sinker of near-identical shape, and they certainly didn’t handle it well when they got to two strikes.
But Brennan has lost a bit of that edge at times, notably for a brief blip in June of 2019, immediately preceding his first IL stint as a Mariner. That right shoulder strain sidelined him for two months, and he returned for barely a week of reduced velocity before regressing to the IL with inflammation. He’d make a few more appearances upon his ultimate activation in September, but he was slightly diminished from the explosive player he’d been in the first couple months. He mustered just a single appearance in 2020 before hitting the IL again, waylaid with an oblique strain, and once again finished the season active, but uninspiring.
It doesn’t take a stats wiz to recognize that more velocity tends to breed more success, and better velocity is only possible with better health. The trend lines on Brennan’s velo are troublesome.
Thus far, when working 94-96, the 29 year old righty has been a brilliant reliever. When he’s closer to 92-94, he’s on much thinner ice, particularly as the scouting report for hitters is relatively clear. His best bet for sticking and succeeding is - easy enough to say - getting healthy and regaining his velocity. Working in Brennan’s favor are a few things. The lengthy winter means plenty of time to heal and regain strength. Seattle is no doubt enthusiastic about keeping Brennan on the 40-man roster as he has minor league options, making him a likely candidate to shuffle between levels in the event that the bullpen needs aggressive management. While traveling between Seattle and Tacoma isn’t exciting as anyone who has sat in the traffic can attest, it does mean consistency of messaging and coaching, hopefully.
Most of all, though, the Mariners just don’t have anyone else quite like Brennan. The side-slinging sinkerballer is the best groundball specialist in the M’s arsenal, and that knack helps him mitigate his occasionally elevated walk rates with double-play balls to his Gold Glove infield. He’ll have to compete with Kendall Graveman and perhaps other external adds, but a healthy Brennan can hang with the best.