Diamondbacks claim reliever Gavin Hollowell off waivers from Rockies

The Diamondbacks had an open spot on their 40-man roster since Tuesday, when Logan Allen was designated for assignment. After clearing outright waivers, Allen elected free agency and re-signed with Arizona on another minor league deal. After claiming Hollowell, the 40-man roster is now full again.

Hollowell, 26, was a sixth round selection in the 2019 draft out of St. John’s University. He debuted with the Rockies on September 19, 2022. The 6’7″ right-hander features a mid-90s fastball that plays up due to deception and an extension that ranked in the 87th percentile in 2023. Due to an unspecified injury, Hollowell appeared in just eight games for the Rockies’ Triple-A affiliate in Albuquerque and pitched to an 11.37 ERA in 6 1/3 innings. The results at the major league level haven’t been great. He has a career 6.20 ERA across 40 2/3 innings. Even accounting for the high run-scoring environment of his home ballpark, that’s an 80 ERA+, 20% worse than the league average pitcher.

Looking deeper into his major league results on Statcast, it appears that hitters are not squaring up his four-seamer. Opposing hitters were batting .182 against the pitch in 2023, with a 32.3% whiff rate and an average launch angle of 32 degrees. That’s an indication that batters are late to pick up on the pitch and are getting under the ball. The slider has some promise, with a lot of horizontal sweep in the low-80s, but he struggles to land the pitch to the right locations consistently.

There is some potential in his arm, and with the team looking for more depth with right-handed relief arms could be an interesting reclamation project. Hollowell has two options left on his contract entering the 2024 season, although it’s been burned this year since he’s spent the entire season in Triple-A. The Diamondbacks would be able to option him to Triple-A in the 2025 season.