Simply put, when a contract tolls, it effectively means it has been put on hold for a year, transferring over to cover the next season instead. The same thing also happened to the contract of Martavis Bryant when he missed a year due to suspension in 2016.
As per the CBA.
“Any player placed on a Physically Unable to Perform list (“PUP”) will be paid his full Paragraph 5 Salary while on such list. His contract will not be tolled for the period he is on PUP, except in the last year of his contract, when the player’s contract will be tolled if he is still physically unable to perform his football services as of the sixth regular season game.”
If not for the Steelers’ decision to restructure the contract of Shazier in 2018, his contract would have tolled at a rate of $8.718 million, but he will now be under contract for one more year at a salary of $805,000 instead.
Shazier will start the year on the PUP list again in 2019 and it should be expected that his contract will toll once more in 2020. But by keeping him on the roster rather than signing him to a coaching role as some have suggested, Shazier will add another year of service to his NFL pension and will be able to continue his rehabilitation at the team’s facilities at their expense.