According to Rapoport, the Ravens are expected to place Monroe on season-ending injured reserve in the coming days.
The Ravens could use the open roster to add a quarterback such as Bryn Renner from their practice squad in the event Matt Schaub is unable to play against Seattle.
Monroe, 28, is in the second year of his five-year, $37.5 million contract that included $19 million guaranteed. He’ll make a base salary of $5.5 million this season and another $7.7 million in 2016.
Assuming this is it for Monroe, he would have appeared in just six games for the Ravens in 2015. Pro Football Focus has him rated as the No. 23 offensive tackle out of 77 qualifying players.