1:57pm: The Orioles have formally announced Mountcastle’s promotion. In a corresponding move, Chris Davis was placed on the 10-day IL due to patellar tendinitis in his left knee.
11:40am: The Orioles are calling up top prospect Ryan Mountcastle for his MLB debut, as first reported by Jason La Canfora of 105.7 The Fan (Twitter link). The 23-year-old slugger was the No. 36 overall pick in the 2015 draft. He’s already on the 40-man roster, so they’ll only need to clear space on the 28-man roster to accommodate him (although the corresponding move could still include a 40-man subtraction, of course).
Mountcastle has ranked among the organization’s best prospects since the time he was drafted out of high school. He has at times ranked among the game’s 100 best prospects according to outlets like Baseball America, MLB.com, Baseball Prospectus, etc. — and he’s currently just on the outside of FanGraphs’ Top 100, sitting at No. 111.
Questions persist about just where on the field Mountcastle will play. He was drafted as a shortstop but has slid down the defensive spectrum — first moving to third base and then spending time at first base and in left field last year in Triple-A. There are far fewer questions, though, about the slugger’s promising bat. Mountcastle followed up 2018’s .297/.341/.464 slash (121 wRC+) in a pitcher-friendly Double-A setting with a .312/.344/.527 slash (117 wRC+) in Triple-A last year. He doesn’t walk much but also doesn’t strike out at an alarming rate and has never batted worse than .281 in a full professional season.
It’s possible that Mountcastle will supplant the struggling Dwight Smith Jr. as the team’s primary left fielder. Smith has posted a woeful .222/.306/.365 batting line in 72 plate appearances this year and wasn’t much better in 2019 when he hit .241/.297/.412. Given that Smith himself has graded out as a poor defender in left, there may not be a dip in glovework at all, and Mountcastle is a clear part of the organization’s future (which cannot be said of Smith).
Mountcastle could also be worked into the corner infield and designated hitter mix, but regardless of the position listed next to his name on the lineup card, it would behoove the Orioles to get him regular at-bats through season’s end. The hope is that Mountcastle will be a fixture in the lineup for years to come, and now that we’ve passed the point where he’d qualify as a Super Two or reach free agency after “only” six years instead of seven, there’s little reason for the O’s to keep him down at the alternate training site. Assuming Mountcastle is in the big leagues to stay, he’d be controllable through 2026 and arbitration-eligible after the 2023 season.
It is, of course, also worth noting that the O’s are just a game below .500 after a surprising start to the season. They’ve dropped five straight and are currently on the outside looking in on the playoff picture, but slotting Mountcastle into the lineup can’t hurt their odds of making a Cinderella run at this year’s expanded playoff format.