Cubs, Diamondbacks Coaching Staffs Have Heated Exchange Over Sign Stealing

Monday night’s game in Arizona was mostly a ho-hum affair in which the Cubs cruised to an easy victory behind an excellent effort from Kevin Gausman. There was a fair bit of drama in the top of the 5th inning, however, as the opposing coaching staffs got into a verbal kerfuffle from across the field. The Cubs had just gone up 2-0 on a Seiya Suzuki double and Michael Busch was at the plate against Arizona starter Merrill Kelly.

Bench coach Jeff Banister and pitching coach Brian Kaplan were visibly upset, with the latter yelling at home plate umpire Lance Barrett about something. Banister then started yelling at Cubs bench coach Ryan Flaherty, who had presumably responded to Kaplan’s claims. The Diamondbacks were upset that the Cubs, specifically third base coach Quintin Berry, was stealing and relaying signs to his hitters.

Kaplan to Barrett: “You know what he’s doing!”
Banister to Flaherty: “Oh, f*ck off. You shut the f*ck up!”
Flaherty to Banister et al: [demonstrative finger wag] “No, no, no! No! F*ck you! F*ck you!”
Banister to Flaherty: [mocking finger wag with sarcastic frown]

The Diamondbacks were pissed that the Cubs third base coach was stealing Merrill Kelly signs

Brian Kaplan: “You know what he’s doing.”

Jeff Banister: “Oh fu*k off… you shut the fu*k up”

Ryan Flaherty: “No, no no…No. FU*K you! FU*K you!” pic.twitter.com/6OqnyOKQeP

— Punchoutpitch (@Punchoutpitch) August 25, 2026

Busch ended up walking, which we’ll get into further in just a bit, then Alex Bregman popped out to first to end the inning. After the home team went quietly in the bottom of the frame, the Cubs busted things open against reliever Taylor Clarke in the 6th with back-to-back home runs from Michael Conforto and Carson Kelly. Those were the first two batters Clarke faced after taking over for his starter, whose final line was better than it should have been.

Kelly is mired in a very rough season that has seen him spraying the ball all over the place for an inflated walk rate, though he somehow managed to throw 60 of 99 pitches for strikes. Changeups accounted for more of that total than any other pitch, 28 to be exact, and the offspeed pitch was at the center of the controversy.

“We just thought [Berry] was relaying signs,” Kelly told reporters after the game. “We thought he had something on my changeup; we thought he was giving — especially the lefties — every time I was throwing a changeup, we felt like he was relaying that.”

Merrill Kelly confirms that the D-backs thought that Cubs third base coach Quintin Berry was relaying signs every time he threw a changeup to lefties.

“Stealing signs is as old as baseball. I think it’s a little bulls— when it comes from a coach.” pic.twitter.com/FEXY5jS6B3

— Nick King (@NickKingSports) August 25, 2026

“Stealing signs is as old as baseball,” Kelly continued. “I think it’s a little bullshit when it comes from a coach. I think if it’s a guy on second base and they see the grip in your glove, or if the hitters can see something that you’re doing with your glove, I think that’s fair game. I think guys have been doing that since the beginning of baseball. I think it’s a little bush league when it comes from outside that…

“That being said, I gotta take a look at what I’m doing, ’cause clearly he had something. And obviously if he has it, then other people will probably pick up on it as well.”

Ah, now we get to the heart of the matter. Kelly has a 5.35 ERA, a 5.69 FIP, and a 7.19 expected ERA. His changeup has generated a -4 run value, 10 runs worse than last year, which puts it in the ninth percentile among MLB offspeed offerings. While that’s much better than his four-seam (-10) and cutter (-8), it’s never a good thing when your bread-and-butter pitch is no longer effective. The other issue is that Kelly throws the change almost twice as often to left-handed hitters.

Its usage was even more pronounced on Monday night, with 21 of the 28 he threw coming against lefties. Busch saw four of them in that aforementioned at-bat, including three in a row, all of which were low and away. In his first at-bat, Busch got three consecutive offspeed pitches to finish Kelly’s first strikeout. During Conforto’s first plate appearance, a walk, he saw four straight changeups. What I’m saying here is that Kelly’s mix isn’t some kind of guarded secret.

So with all due respect to the unwritten rules of the game, I think the Diamondbacks might need to direct more of their energy into figuring out how Kelly is clearly tipping his pitches. This isn’t like the days when they had Randy Johnson, who clearly indicated whether he was throwing fastball or slider. The difference is that it didn’t matter whether hitters knew what was coming when prime Big Unit was on the mound.

If this were happening 20 years ago, Pete Crow-Armstrong or another prominent Cub would have been plunked. Instead, it’s probably something we’ll all forget about by the time Tuesday night’s game rolls around. That’s almost too bad, because I have to admit to having a soft spot for baseball’s particular brand of at-a-distance animosity. It usually amounts to nothing, but I always get a chuckle out of it.

It’s even funnier when you watch the others around Flaherty in the dugout: Craig Counsell doesn’t budge and Nico Hoerner just sits there like nothing is happening. This is about as close as we get to Andre Dawson throwing all the bats from the rack onto the field or Lou Piniella picking up a base and chucking it, so I’ll take what I can get when it comes to baseball’s unique brand of redassery.