"Antonio is playing at that type of level at wide receiver, a J.J. Watt-type of level," Tomlin said Tuesday at his weekly news conference. "He's one of the best in the world at what he does and he's mentally and physically on top of his game."
Brown leads the NFL with 60 catches and is second with 852 receiving yards. The former sixth-round draft pick is on pace to catch 120 passes for 1,704 yards, which would set Steelers season records.
Brown set the franchise's season receiving record in 2013 with 1,499 yards and he has been even better this season despite consistently facing double-teams.
"He's a known issue [for opponents] but he still performs," Tomlin said. "We can say similar things about guys like J.J. Watt. We knew what he was capable [of] when we were getting ready to play him but it still doesn't stop the storm from coming."
Brown already has seven touchdown catches, one fewer than he had last season, and last Sunday the two-time Pro Bowler caught 10 passes for 133 yards and two scores in the Steelers' 51-34 win over the Indianapolis Colts.
Against the Colts, Brown extended his NFL record of consecutive games with at least five catches and 50 receiving yards to 24.
"I have never seen anybody utilize their hands, feet and eyes the way that he does," quarterback Ben Roethlisberger said. "You get the ball in his hands and a big play can happen at any time."
Roethlisberger's Big Day Propels Steelers
Ben Roethlisberger threw for 522 yards and six touchdowns to lead the Steelers past the Colts 51-34.
Sunday Blitz: Colts-Steelers Recap
Jim Basquil and Eric Allen break down the Steelers' 51-34 win over the Colts.
QB Report: Roethlisberger's Record Day
Kevin Seifert looks at why Ben Roethlisberger was able to light up the Colts in week 8.
Sport Science: Antonio Brown's Precise Routes
Steelers wide receiver Antonio Brown is so good at running precise routes that he can do it blindfolded.