Cubs Sign Free-Agent Reliever Colten Brewer and His New Slider

It won't have anyone crossing Josh Hader or Robert Stephenson off their wish lists, and it's not even likely to be a big-league deal, but the Cubs have inked right-handed reliever Colten Brewer for 2024. Breaking the news on New Year's Eve: Brewer himself. 

In parts of five big-league seasons, Brewer has fewer than 100 innings pitched, and he spend the second half of last season overseas. Still, it's an interesting pickup, and a good fit for the Cubs' pitching predilections. Brewer throws a hard cutter, very much his primary fastball, rather than acting as a type of breaking ball. With that pitch sitting in the mid-90s and a curveball that can be nasty when he has command of it, he's not only broadly appealing, but exactly the kind of pitcher the Cubs like to target. If they could sign nothing but guys with unusual cut on their fastballs and a breaking pitch that paired well with it vertically, they would do so. 

Still, it's tempting to dismiss this move as mere filler. Brewer is over 30, has only rarely filled a regular role in a big-league bullpen, and is almost certainly signing a non-guaranteed, minor-league deal with an invite to big-league spring training. That doesn't move the needle, even by the low standards of relief pitcher signings.

There's a little more meat on the bone than you might think, though. As you'd expect of a guy whose repertoire is mostly cutter-curveball, Brewer has historically had reverse platoon splits, across all levels of professional baseball. Righties had a higher OPS against him every year from 2018 through 2022, and it was often by a wide margin. When he's gotten hit hard or had major control problems, the trouble has mostly come against fellow righties. 

In 2023, though, right-handed batters were considerably worse than left-handed ones against Brewer. This data is only for the very limited time he got Stateside, and the samples are minute, but in 61 plate appearances, righties struck out 21 times, drew just four walks, and had an anemic .514 OPS against him. That could be random noice, but the strikeout rate suggests that there's something real there, and pitch data fills in the gaps.

This season, Brewer finally found a slider with more lateral tilt and greater velocity separation from his cutter. Here's the year-by-year chart of his velocity by pitch type.

He also got more horizontal movement and more depth on the pitch, relative to that cutter that stands in for a more typical pitcher's four-seam fastball or sinker. 

You can call it a sweeper, or not, but it was a different and more effective pitch than the previous sliders he'd tried. Brewer had spent spring training with the Rays, but the Yankees scooped him up just after Opening Day, and they excel at helping pitchers engineer just this type of slider transformation. Brewer got so comfortable with his newly redesigned slider that it took over for his curve as the primary breaking ball in his attack.

There's still little chance that Brewer will emerge as more than a middle reliever, and given the Cubs' current bullpen options, he's no lock to so much as take the mound for the team in 2024. Still, considering the terrific success he had in Japan and the material changes he made this season, it's a nice little pickup. Presumably, the Cubs like the upside in his new breaking ball, and we know how nicely what he was already doing pairs with the Cubs' organizationl approach.

What do you think of Brewer? Is there anything here? Would you rather have him or, say, Jose Cuas at the bottom of the bullpen depth chart in 2024? Speak your piece below.