Relief pitchers are the most volatile group of players in baseball. There are countless examples of unknown commodities making meteoric rises out of nowhere and superstars flaming out in the blink of an eye. Often, it’s the same pitcher a few years apart. Several of the most dominant relief seasons in MLB history were nearly impossible to have foreseen beforehand.
Nevertheless, there’s no harm in dusting off the crystal ball and giving it a peek. Some bullpen aces rise from the depths of failed starters or minor league journeymen by complete surprise, but often there are subtle signs of latent potential waiting to be tapped into.
With pitchers and catchers reporting to spring training in about a month, let’s consider what relievers might be walking into camp with a career year at their fingertips.
Relief pitcher breakout candidates in 2025
For this second installment of my 2025 breakout picks, I will follow up my starting pitcher analysis by analyzing relievers bound for breakouts. In my analyses, I will be using a project of mine called LASR (League-Adjusted Standardized Rating) which places all stats onto the same 20-80 scouting scale based on league qualifiers. On the scale, 50 is average and 10 points in either direction is one standard deviation (all data is sourced from FanGraphs).
The relievers I’ve chosen had a wide range of outcomes last season, so a “breakout” this year might look different for each of them. Generally, I am predicting them to take significant steps ahead in their performances, whether that means better results, sustained success over larger sample sizes, or both. So, let’s make a call to the pen (sorry, I had to) and see who’s warming up to surprise us in 2025.