In a nutshell, show up.
"The first rule of getting better is showing up," Brown told reporters on Wednesday. "You can't make anything better without showing up. ... (To) make everyone understand where he wants to be -- he wants to be here not just for this year, but years to come -- come out here and show up. Show up and get better and show guys you're serious."
Bell has been absent from the voluntary workouts while bracing for a second straight summer of franchise-tag negotiations. He earned $12.12 million on last year's tag and would take home $14.5 million this season unless a long-term deal is reached by July 16.
While Bell is dealing with the franchise tag, Brown did not hold out for his new deal in which he was outplaying the six-year, $43 million contract he signed in 2012. Brown ultimately received a four-year, $68 million extension in February 2017.
Bell and Brown reportedly have texted in the offseason.
"We all know Le'Veon is a competitor and is highly conditioned, always taking care of his body and putting himself in high condition," Brown said. "The one thing about Le'Veon that makes him special, he takes his game seriously. It's never a question or doubt about his game: Is he physically ready? I know when he walks in the building, whenever he shows up, you know what you're going to get -- you're going to get a guy who's ready to take 400 to 500 carries, a guy who's willing to run and catch the ball, a guy who can do it all."
Guard Ramon Foster, who is the Steelers' union representative, doesn't have an issue with Bell's absence.
"He's (not) under contract right now, so he has no obligation (to participate)," Foster said, per the Pittsburgh Tribune Review. "My thing with that and everybody else is the business side handles itself. I am sure he is working his butt off like he always has. He did the same thing last year as far as how many days he missed, and he was (No. 3 in the NFL) in rushing. So we are not worried about that."
The 48th overall pick in the 2013 draft, Bell ran for 1,291 yards and a career-high nine touchdowns last season while catching a personal-best 85 passes for 655 yards and two scores. He was third in the NFL in rushing yards and 10th in receptions.