Antonio Brown's resentment grew with each JuJu Smith-Schuster reception

Max: AB showing a lot of insecurity by coming after JuJu (1:35)

Max Kellerman tries to make sense of the Twitter beef between Antonio Brown and JuJu Smith-Schuster, saying Brown is insecure about his time in Pittsburgh. (1:35)

PITTSBURGH -- Wide receiver JuJu Smith-Schuster had a clear plan from the moment the season ended: Don't dip into the Antonio Brown mess.

Smith-Schuster wanted to focus on his development on and off the field. He showed support for his fellow wide receiver from the Pro Bowl but made clear he wouldn't be involved. Beside, Smith-Schuster never had a problem with Brown, and any issues Brown had with quarterback Ben Roethlisberger didn't really concern him.

It concerned Brown, whose first snip at Smith-Schuster two weeks ago was subtle. Brown's double-up left Smith-Schuster little choice but to respond.

To be clear, Smith-Schuster wasn't at the core of Brown's undoing in Pittsburgh, which included feeling like a scapegoat for the team's late-season implosion. Brown had more relational issues with coach Mike Tomlin and Roethlisberger. The two receivers were cordial, with Smith-Schuster deferring to Brown at every turn, out of respect for his All-Pro pedigree.

The presence of Smith-Schuster -- what his rise represented -- was very much the issue.

Nearly everything in the NFL comes down to money, and Smith-Schuster was messing with Brown's bottom line. Smith-Schuster's targets were increasing, his adoration from Roethlisberger growing, and with that, a mega-extension in 2020 inching closer. Brown was nearing his 31st birthday without guaranteed money while Smith-Schuster was dancing his way into Brown's own endorsement deals.

"JuJu was in AB's Pizza Hut commercials -- you don't think that got to [Brown]?" one team source said. "JuJu was coming up and that became a problem for AB."

Smith-Schuster winning the Steelers' most valuable player award, as voted on by teammates, seemed to make matters worse. Many inside and outside the building believed Brown harbored resentment over that voting, though it was never really talked out. Roethlisberger's support of Smith-Schuster throughout the season, even failing to call Brown his No. 1 receiver after Week 12, loomed large.

What's curious to teammates now is many felt they had a great relationship with Brown. Despite his issues with punctuality and star treatment and sideline flare-ups, they respected his jovial encounters with even the lowest locker-room rungs and the way he worked.

Leaving the team in Week 17 hurt, but players cautiously welcomed him back. His bizarre social media behavior in the weeks after rendered those efforts futile.

Now, former teammates who were over the maelstrom months ago are left wondering if Brown can get any more petty than posting screenshots of an impressionable Smith-Schuster sending a direct message to Brown in 2015, asking for help.

Smith-Schuster once recalled that message during his first offseason workouts with the team. What he said about Brown's response was unmemorable now, presumably because he didn't get one.

Ask almost any Steeler about what went down late last season and they instantly want to move on. But they know this: Two Steelers receivers have come at Smith-Schuster publicly (Brown and Martavis Bryant), and he's the only one left.

Despite the obvious talent drain in Pittsburgh with Brown, Le'Veon Bell and Ryan Shazier all out of the lineup, the Steelers believe rallying behind young players such as Smith-Schuster, T.J. Watt and James Conner will usher the team past the grudges Brown clearly still holds.

"Quality men who happen to be quality players," Tomlin said. "It starts there."