The Cubs and left-hander Aaron Bummer have agreed to a minor league deal, reports Bob Nightengale of USA Today. The O’Connell Sports Management client will presumably report to Triple-A Iowa at some point in the coming days.
Bummer, 32, was just released by Atlanta last week. He was having an awful season, posting an earned run average of 7.63 over 15 1/3 innings. His 46.2% ground ball rate was decent but his 16.9% strikeout rate and 13% walk rate were both awful figures. Even more alarming is that he’s already been tagged for six home runs. His final appearance with the team saw him give up six runs on three hits and five walks in one inning against Miami.
Rough as this season has been, Bummer was a quality left-handed bullpen piece for Atlanta in 2024-25. He posted a sub-4.00 ERA in both years with plus ground-ball rates. Bummer had a strong 28% strikeout rate two seasons ago, but that fell to a pedestrian 21.7% mark last year. It proved an alarming precursor to his first couple months of 2026.
Bummer is a sinkerballer who was in the mid-90s for the majority of his career. His average velocity fell to 91 mph last season and is at a career-low 90.2 mph mark this year. He missed the final five weeks of the ’25 season to shoulder inflammation. Bummer hasn’t gone on the injured list this year, but the 32-year-old’s stuff clearly isn’t as sharp as it was not that long ago.
Atlanta is paying Bummer a $9.5MM salary for the 2026 season. They’re on the hook for that money aside from the prorated $780K league minimum for any time he spends on the MLB roster with another club. The Cubs have Caleb Thielbar, Hoby Milner and Ryan Rolison as southpaws in Craig Counsell’s bullpen. Luke Little, Luis Peralta and swingman Doug Nikhazy are on optional assignment. Bummer will join them in Iowa as he looks for his 2024-25 form.
Photo courtesy of Brett Davis, Imagn Images

Cubs need a lot more than Aaron Bummer
Some folks just have unfortunate names.
He can help out with that losing streak.
I always check the comments first when there’s an article about Bummer!
Let me be the first to announce that the Cubs are NOT going to be buyers at the deadline this year.
The rest of you can accept that fact in your own time.
As Brett Taylor would day, with his usual insufferable smarminess: (sigh)
What a Bummer. Another loss for the Cubs. They certainly can’t see this as a win. But then again the Cubs could draw a line straight across the top of the ‘W” on their flag and turn it to the left and wave the new flag with a “B” when Bummer comes out of the bullpen! Dumb and Bummer!
If they want a LH guy who walks a bunch of guys just bring up Luke Little. Done.
Haven’t been able to develop their own pitching for a long time.