They were back at it in Pittsburgh on Wednesday, the Cubs and Pirates coming to a head over the second questionable slide in a three-game span. This time it was the Pirates hitting the dirt, as pitcher Joe Musgrove powered into second with a blatantly late slide in an effort to disrupt a double play. (Watch it here.)

This time it was Javy Baez on the receiving end, and though the slide did no damage, he wasn’t pleased. Musgrove leaped so late that he landed virtually atop the bag, his momentum carrying him straight past it. In so doing he violated two of the four tenets of Rule 6.01(j), which we’ve heard an awful lot about recently. It reads:

If a runner does not engage in a bona fide slide, and initiates (or attempts to make) contact with the fielder for the purpose of breaking up a double play, he should be called for interference under this Rule 6.01. A “bona fide slide” for purposes of Rule 6.01 occurs when the runner: (1) begins his slide (i.e., makes contact with the ground) before reaching the base; (2) is able and attempts to reach the base with his hand or foot; (3) is able and attempts to remain on the base (except home plate) after completion of the slide; and (4) slides within reach of the base without changing his pathway for the purpose of initiating contact with a fielder.

Baez knew that Musgrove’s slide wasn’t by the book, and as the pitcher started back toward Pittsburgh’s dugout, let him know about it. Things hardly grew heated—Baez gently put a hand on the Musgrove’s hip in a “there, there” kind of way—and though benches cleared, players never came close to fighting.

For a blog about unwritten rules, we’ve sure spent a lot of time recently on the written ones. Still, there’s an awful lot of subtext here. Musgrove’s slide was about much more than hard-nosed baseball—it was about retaliation for Anthony Rizzo’s disputed takeout of Pittsburgh catcher Elias Diaz on Monday. Musgrove admitted as much, telling reporters after the game: “I was trying to go in hard like their guy did. [Baez] should’ve got out of the way, I guess.”

Not enough? The pitcher elaborated.

“We’re not trying to fight anybody here,” he said in an MLB.com report. “We’re not trying to cause any problems, but you blindside our catcher when he’s got no chance to defend himself … That’s something that I feel like is part of baseball. I don’t think he was happy that I went after their guy or anything like that, but yeah, you try to pick up your teammates where you can. I didn’t hurt him. I easily could have made a dirty slide, but I feel like I made a clean slide and went in hard.”

It’s a simple message. The cleanliness of Musgrove’s slide is up for debate, but his claims about not wanting to injure anybody are valid. Baez himself believed them, telling reporters after the game: “I’m not saying it was a bad slide, but he just went hard. I asked him, ‘What was that about?’ He said, ‘Sorry,’ and the conversation was over.”

Musgrove sent a message, to the Cubs and his own team alike, that plays like Rizzo’s will be answered. It was a canny decision. As a pitcher, Musgrove easily could have conveyed the sentiment with a message pitch, but by going slide-for-slide, he was able to provide tangible support for his teammates in an aboveboard fashion.

Musgrove—a third-year pitcher trying to establish himself after coming over from Houston in the Gerrit Cole trade—earned a measure of clubhouse standing with seven innings of one-run ball on Wednesday. He may have earned even more with his slide.