Dyson's practice squad contract with the Vikings was disapproved by the NFL on Wednesday, Aaron Wilson of KPRC 2 Houston reports.
The issue comes from the timing of Dyson's contract, as he was waived from the Vikings' injured reserve Saturday with an injury settlement, per Alec Lewis of The Athletic. Dyson is a free agent again, and it's possible that he returns to Minnesota once the terms of the settlement have been satisfied.