The Rockies will have, at most, rookie Ben Bowden in the bullpen as a lefty so Jerry Blevins is the first of two left-handed relievers on this list.
Blevins, 37, was released by the Mets in his second stint with the club after he pitched to a 3.18 ERA in 5 2/3 IP. His problem was control as he walked four batters in that span.
However, the veteran lefty didn’t pitch in 2020 as he wasn’t signed by anyone but he still pitched well in 2019 as, in 45 games, he pitched to a 3.90 ERA (122 ERA+). He struggled a bit in 2018 (4.85 ERA) but had a sub-3.00 ERA in both 2016 and 2017 in 73 and 75 appearances.
The other problem with Blevins would be the “three-batter minimum” rule as in the 73 and 75 appearances he had in 2016 and 2017, he only pitched in 42 and 49 innings.
But considering how he pitched in spring training for the Mets, Blevins looks like he’s still got it so, perhaps, the Rockies could use him as a lefty reliever and, perhaps, even a mentor to some of the Rockies current lefties, like Kyle Freeland, Austin Gomber, Ryan Rolison, and the aforementioned Bowden.