In the article below it says Pittsburgh offered Bell 10M upon signing and an additional 10M roster bonus due Sept 1 2018 and 47M total in the first three years.
From an article on SteelersDepot.com -
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... Before any of you start commenting about the contracts that were ultimately signed this offseason by fellow NFL running backs Todd Gurley and David Johnson, make sure you have your facts straight when it comes to the “fully guaranteed” money that each was given and the new money cash flow for each.
Gurley’s “fully guaranteed” money that he received when he signed his four-year, $57.5 million contract extension with the Los Angeles Rams on July 25, 2018 was all of
$21.95 million and that includes the $21 million signing bonus given to him. The $45 million in total guarantees that was initially reported when Gurley signed his deal is a virtual guarantee total and I bet not many of you have taken the time to read the details of that contract Florio posted a while ago that explains the rolling structure. If you haven’t, shame on you.
As for the three-year, $39 million contract extension that Johnson signed with the Arizona Cardinals on September 10, 2018, his fully guaranteed money in that deal works out to be
$24,682,500 and that includes a signing bonus given to him in the amount of $12 million. His injury guarantees work out to be just a little less than $32 million, the first three years of his deal.
From 2018 through 2020, Gurley and Johnson will have earned $40 million and $31.8825 million, respectively, whereas Bell would have reportedly earned $47 million in those same three years had he accepted and signed the contract the Steelers reportedly offered him. ... "
Full article is here -
https://steelersdepot.com/2018/10/new-report-says-steelers-final-offer-to-bell-included-47-million-in-first-3-years/