Orioles 2021 #15 Prospect Zac Lowther – LHP


Ended an up and down 2021 season in the Orioles rotation throwing well in three of his five September starts, landing him as the #15 prospect.

Zac Lowther
Pos: LHP
Bats: L
Throws: L
Age (as of Jun 30th) : 25
2021 Level: AAA/MAJ (Plus rehab)

Pitches (current/future value)
Fastball: 40/45
Change: 40/45
Slider: 50/55

Curve: 50/55
Command: 40/50


Most Likely Future Role: 4th/5th starter
Ceiling: 4th starter

What we know: This longtime top prospect made his major league debut in an an up and down season that saw him promoted to the major league team on six occasions before finally getting put into the Orioles rotation for good in September. Never able to get into a real routine with the yo-yoing up and down, Lowther didn’t pitch well in AAA either and eventually landed on the injured list at Triple-A Norfolk with a left shoulder strain on July 20th. He started a rehab assignment a month later and made his way back to Norfolk for one start on September 1st before getting his final promotion to the Orioles rotation for the rest of the year.

Lowther has a funky delivery and 7.0 extension on his fastball (6.5 is major league average), but it has below average velocity (90.7) and vertical drop, but has 95 percentile horizontal movement (tail) that should have played better, but he found too much of the heart of the strikezone with the pitch and major league batters tee’d off for a .442 wOBA. He found some success with getting swings and misses up in the zone, but he’s going to need much better command of the pitch for it to be effective.

He didn’t seem to have the feel for his changeup much of the season and it too get hit hard and often. With below average drop to the pitch, it far too often floated up to the plate and batters put up a .570 wOBA against the pitch. For some reason he used his changeup more than his more successful curveball and slider early on before pitching more with his breaking balls late in the year when he had success.

Both his curveball and slider showed above average movement and had success with both pitches holding batters to a .179 (curveball) and .244 (slider) wOBA.

What we don’t know: Was Lowther’s season of inconsistency due to the Orioles handling of him or is it because his stuff doesn’t play? While all of his pitches have at least one aspect of average or plus movement, will he ever have the command for his stuff to play? Can he find the feel for his changeup again and can it improve?

What we think: Lowther really had a lost of year, but how the Orioles handled him by bringing him up and down, putting him in relief, never allowing him to settle into a starter’s routine in AAA did him no favors. It’s almost amazing that the organization would treat him so hap haphazardly when they were in such dire need of starting pitching. They treated him like a non prospect organizational guy instead of a future potential piece of their starting rotation.

Next year the Orioles will have a better chance to know what they have in Lowther. While the fastball velocity will always hold him back from being more than a back end starter most likely without improvements to his command or changeup, his plus breaking stuff and ability to miss bats up in the zone give him a good chance to pitch as a starter. While the AL East is tough place for any pitcher to pitch, Lowther goes into 2022 having to pitch himself out of the rotation next year.

Previous articleAFL Game Summary (11/9)
Next articleOrioles 2021 #16 Prospect Carter Baumler – RHP
Tony has owned and operated Orioles Hangout since 1996 and is well known for his knowledge of the Baltimore Orioles organization from top to bottom. He's a frequent guest on Baltimore-area sports radio stations and can be heard regularly on the 105.7 FM The Fan. His knowledge and contacts within the Orioles minor league system and the major league baseball scouting industry is unparalleled in the Baltimore media and is known as an expert on the Orioles prospects.