Cubs Sign Aaron Bummer to Minor League Deal

Bummer is no stranger to pitching in the Windy City, as he spent seven seasons on the South Side of town with the White Sox. From 2017 to 2023, the southpaw was a dependable bullpen arm and appeared in 289 games, logging a 3.84 ERA and 3.38 FIP with 309 strikeouts over 272.0 innings pitched.

In 2024, Bummer was traded to the Braves for five players including starting pitcher Mike Soroka and infielder Nicky Lopez. His first two seasons in Atlanta were also solid, posting a 3.69 ERA over 109.2 innings. However, 2026 has been nothing short of a disaster for Bummer.

Before being released, the lefty posted a ghastly 7.63 ERA and 8.62 FIP over 19 appearances and 15.1 innings, amounting to -0.8 fWAR. His fastball velocity has declined significantly, now reaching just over 90 mph after being in the mid-90s as recently as 2023. With lower velocity and worse pitch movement in general, Bummer has only struck out 16.9% of the batters he's faced while registering a 1.83 WHIP and surrendering six home runs.

Despite Bummer's decline, the Cubs are in desperate need for any kind of production from the mound. Chicago's relievers have combined for -0.2 fWAR over 200.1 innings and allowed 28 home runs while averaging only 7.95 strikeouts per nine innings. The Cubs have seen a wave of pitching injuries over the course of the year, both in the starting rotation and bullpen. As a result, the club is on a 10-game losing streak, their longest since 2022, just weeks after reeling off two 10-game winning streaks.

Based on what Bummer has done this year, he likely won't fix the Cubs' pitching issues. But with so many arms lost to injury, they have no choice but to take a flyer on the lefty and hope he can find his past form.