PITTSBURGH -- As multiple NFL free agents sign contracts with guarantees in excess of $50 million, the Pittsburgh Steelers will happily sit out that bidding. Pittsburgh typically guarantees only the signing bonus on its contracts, and no Steeler save Ben Roethlisberger has gotten more than $19 million on that bonus.

Other teams apply this method sometimes, too, but the Steelers are among the most stubborn with it, never guaranteeing a salary, maybe including a Year 1 roster bonus if they're feeling really generous.

And that's at least in part why Le'Veon Bell and Antonio Brown torpedoed the 2018 season and are now with new teams. Both players tried to work the system -- to varying success -- in the name of more guaranteed money, despite the Steelers' history of retaining hardworking, productive players for the duration of their mega-deals.

This creates a natural question: Will the team eventually change its model to accommodate big-money players? At least one prominent NFL agent wonders.

"At some point, they are going to have to change the way they do their deals," said the agent, who has negotiated with the Steelers in the past. "In most cases it works out for them, but you're seeing more and more that top players are valuing the security of a true guarantee as opposed to a loose guarantee."

To be sure, it's not like the archaic structure can't be pro-player. Take Bell, who could have made around $45 million in the first three years of the five-year, $70 million deal the Steelers offered last year. Bell turned it down because of what he considered a low guarantee of $17 million. The Steelers would have had no plans to cut Bell within the first few years of that deal. They know that'd set a poor precedent for future deals.

But Bell didn't want to assume the risk.

Instead, he sat out the year and is getting $26 million over the first two years with the New York Jets. Over that three-year span, Bell is set to receive $19 million less than had he played three years on the Steelers' last offer.

Bell's plan had its holes, but what's clear is the push for guarantees is growing by the season. Star players are becoming more emboldened. After holding out in Oakland, Khalil Mack got $60 million guaranteed in his new deal with the Chicago Bears. Fellow holdout Aaron Donald came over the top with $86 million guaranteed.

Only the top-shelf players can get away with this. Brown is clearly that, so he forced his way to Oakland, which had $30 million in guarantees waiting for him. Brown failed to show up for work Week 17 and disparaged the Steelers organization publicly and still got what he wanted, an elaborate power play most aren't willing to execute.

Bell sat out the season after two years of rocky franchise-tag negotiations and entered free agency.

Those two Killer B's presented a perfect storm for Pittsburgh, which can mostly operate around those problems. Recent extensions for linemen Cameron Heyward, David DeCastro and Stephon Tuitt are worth $50-plus million in total but offered guarantees of between $15 million and $17 million. Those players didn't have major issues with that because they had one year left on their rookie contracts when they signed, and they understood the situation: Play hard, produce and the security will be there.

In most cases, players take the Steelers' offer and trust the team will act in good faith. The first year is basically guaranteed anyway, and the Steelers like to restructure deals, which makes players harder to cut or trade (see: Brown's $21 million dead-money hit still on the books).

And the Steelers don't spend enough in free agency to run into issues. Cornerback Steven Nelson just signed a three-year, $25.5 million contract that includes a $7.5 million signing bonus as the only true guarantee. Pittsburgh is an attractive free-agency destination to him for reasons unrelated to on-field performance.

"The vibe around here, it's very chill," Nelson said. "It's like a family. I've heard great things already."

However, Nelson is not Bell and Brown, who might have exposed future problems for the organization if it runs into more top players eager to rattle the system.