"Trade me let's find out," Brown tweeted.
The response was directed to Ryan Scarpino, who worked for the Steelers from 2010-17 and tweeted about Brown and quarterback Ben Roethlisberger on Monday: "AB needs to thank his lucky stars, because he was drafted by a team that had Ben. And Ben got AB paid. You know darn well he wouldn't put up those numbers for other teams."
While a Steelers employee, Scarpino was inside the locker room daily and had interactions with players.
Brown posted 67 receiving yards on nine catches and 17 targets, but the CBS broadcast caught Brown in a confrontation with offensive coordinator Randy Fichtner on the sideline. Later in the game, Fichtner spent a few minutes speaking to Brown alone on the bench, then rubbing his head.
Trade me let's find out https://t.co/4OeepI78zy— Antonio Brown (@AB84) September 17, 2018
ESPN left a message with Drew Rosenhaus, Brown's agent, regarding Monday's tweet. The team has not commented on the matter.
Linebacker Bud Dupree said Monday the team knows Brown doesn't want a trade and believes he was simply venting after a tough loss.
"You know how AB is, especially after a loss like that," Dupree said. "Guys are going to say things. He just wants to help the team win as much as he can. We know he'll be ready. He does great things there. He always knows we got him."
Brown has posted five straight 100-catch seasons, and many of Roethlisberger's best statistical seasons have come while playing with Brown in his prime.
On the Steelers' final drive of the Chiefs game, Roethlisberger appeared to wave in Brown's direction after a third-down play at the goal line. When Roethlisberger scored on a fourth-down scramble, Brown walked to the sideline alone while the rest of the offense celebrated in the opposite corner.
This isn't the first time in the past week Brown has made waves on social media. On Wednesday, Brown apologized for a tweet threatening ESPN senior writer Jesse Washington over a story on The Undefeated titled, "Antonio Brown is an Instagram All-Pro. But is that the full picture?"
Steelers guard David DeCastro said players are aware of Brown's tweet to Scarpino, but he's not worried about it.
"I think it'd be easier for all of us to worry about football," DeCastro said of players' use of social media. "But this is the day and age."