Adam Schefter breaks down how Le'Veon Bell's holdout with the Pittsburgh Steelers could cost him in the future. (0:50)

The Pittsburgh Steelers are open to offers for star running back Le'Veon Bell, but no trade talks have advanced to a serious stage at this time, league sources told ESPN.

Some teams have inquired about Bell, while others are mulling whether to make a move, but none has been aggressive so far, according to sources.

Meanwhile, Bell's continued absence from Pittsburgh has raised questions about what his future salary could and would be if the Steelers, or any team that traded for him, used the transition tag on him this offseason.

If any team used the transition tag on Bell next season, the tag number would be 120 percent of this season's salary.

But the longer Bell holds out, the more his salary for this season drops, which could dramatically affect what he earns in 2019. If Bell were to report to the Steelers next week, the most he could make this year would be $11.12 million; and 120 percent of that number under the transition tag would be $13.346 million -- lower than the $14.534 he was scheduled to earn under the franchise tag this season.

With each additional week Bell misses, his 2019 salary potentially drops lower. If Bell reports to the Steelers midway through this season, his transition tag salary for next season could be as low as $9.24 million.

Bell and his agent could argue they are entitled to more, and appeal it to an arbitrator, who could potentially rule in their favor. Bell has refused to sign his franchise tender and already has forfeited $3.41 million by missing Pittsburgh's first four games.