The Royals and left-hander Aaron Bummer have agreed to a minor league deal, reports Jon Heyman of The New York Post. The lefty reported to Triple-A Omaha today and should be in that club’s bullpen once the paperwork is officially completed, if it hasn’t been already.
Bummer, 32, has a strong track record but his recent trend lines are down. From 2019 to 2025, he posted a 3.70 earned run average across 328 innings. He struck out 26.8% of batters faced in that span, gave out walks at a 9.9% clip and induced grounders on 64% of balls in play.
There were some signs of worry last year, though he managed to finish the season with a respectable 3.81 ERA. His ground ball rate had dropped to 53.9%, still well above average but a career worst for him. His strikeout rate also went to 21.7%, a drop of almost seven points from the year before. That all coincided with a loss of velocity. Bummer averaged 94.7 miles per hour with his four-seamer in 2023 but that dropped to 93.6 mph in 2024 and then 91.7 mph last year.
Those trends have gotten even worse in 2026. Bummer made 19 appearances with Atlanta with a 7.63 ERA. His 46.2% grounder rate was still better than par but another big drop relative to his previous work. His strikeout rate plummeted even further to 16.9%. His four-seamer averaged 90.5 mph.
Atlanta released him in mid-May. Bummer then landed a minor league deal with the Cubs, who initially sent him to their Arizona Complex. He eventually made his way to Triple-A Iowa. He made four appearances there, allowing four earned runs in four innings. His velo ticked up slightly to 91.4 mph in those appearances, though he only punched out 3 of the 19 batters he faced. He opted out of that deal last week.
For the Royals, there’s no real risk in sending Bummer to Omaha to see what happens. He is making $9.5MM this year but Atlanta is on the hook for that after releasing him. If the Royals decide to call him up, they would only have to pay him the prorated league minimum for any time spent on the roster, with that amount subtracted from what Atlanta pays.
Kansas City has suffered a number of injuries to its pitching staff. Starters Cole Ragans, Kris Bubic and Stephen Kolek are on the injured list, putting more strain on a bullpen that currently has Carlos Estévez, James McArthur, Nick Mears and Connor Seabold on the IL.
For the season, Royals relievers have a collective 5.42 ERA, which is worse than every MLB club except for the Athletics. The current group might also get thinned out since the Royals are in clear seller position, so they might flip a few arms to other clubs. There’s a path for Bummer to get back to the big leagues if he shows some signs of life with the Storm Chasers.
Photo courtesy of Brett Davis, Imagn Images
