The Mariners have firmed up their 40-man roster ahead of today’s 3 PM deadline to protect players from the Rule 5 draft, and opted to protect four players. This is a few more than we projected them to keep, but the additions aren’t surprising.
OF Taylor Trammell was an obvious choice to add; he’s a Top-100 prospect who was the primary target in the Austin Nola trade with San Diego and someone the Mariners are said to have been interested in for a while. An MLB-adjacent player with upper minors experience, TT was already a lock to be protected, but he added to his case with a strong performance both at the alternate site in Tacoma and in the fall development league, where he was somewhat unfairly unleashed against a crop of unsuspecting pitchers and lit up the box score seemingly every game.
RHP Juan Then, traded away and then re-acquired from the Yankees in the Edwin Encarnación trade, was almost as much a lock as Trammell, despite being only 20 years old and never pitching above A ball. Even pitchers who have completed some Advanced-A are a risky Rule 5 move for teams, but Then’s uptick in stuff—he’s reportedly lighting up the radar gun in the high-90s now, teamed with a legit slider—plus his move to the bullpen fast-tracking his career would have been appealing for a team that had space to stash him in the bullpen for a year. The Mariners have invested a fair amount of development in Then, though, and team officials have been glowing in their praise of the young righty, so this move was fairly well-telegraphed ahead of time.
The other two adds are slightly more surprising. RHP Sam Delaplane was next on the list of consideration given his high-minors experience and strong numbers, but the Mariners kept him at the alternate site all season instead of giving him a chance in literally the worst bullpen in baseball. There have been some reports that Delaplane’s velocity—fringe-average at best—has been down, and he has struggled with some biceps tendinitis in the past, so maybe the team just wanted to slow-play their young reliever while eyeing up a spot for him in 2021. With his dazzling strikeout numbers, high-minors experience, and some national exposure from a strong performance in the Arizona Fall League last season, Delaplane would have been a popular target in the Rule 5, so it’s good to see the team hold on to one of their home-grown projects from that vaunted Arkansas bullpen.
Speaking of that bullpen, the final addition came as a bit of a surprise for me, given that the team snubbed RHP Wyatt Mills when it came time to issue invites for the alternate training site. Mills was invited to the fall development league, where he spent his time doing exactly what a seasoned sidearm pitcher should do while facing a lot of early-development prospects: ruthlessly mowing them down one after the other. Mills, like Delaplane, had reportedly suffered a little velocity dip in Spring Training 1.0, but from what came out of the development camp, it looked like he was back to his mid-90s form this fall.
With these four adds, the Mariners’ 40-man roster is now one player away from being full, leaving little room for big free-agency signings, something that was probably not going to happen anyway. There’s still some room to cut some bullpen chaff off of the roster [stares in Walker Lockett], but things have tightened up significantly. This could be an indicator that the Mariners, for the first time in three years, might not be active in the Rule 5 draft, although there’s seemingly always room in the banana stand for a misfit toy relief prospect, and they could just as easily swap out late-season waiver claim Domingo Tapia for one of the available players if they so desire. Dipoto did promise to add to the bullpen this off-season; apparently he’s starting by surveying the contents of the Mariners’ own cupboard.