Swanson, 27, is a former third-round pick of the Lions back in 2014. He played out the final year of his four-year, $2.96 million rookie contract that included a $619,472 signing bonus and made a base salary of $1,772,000 for the 2017 season.
Swanson is now in position to be an unrestricted free agent for the first time in his NFL career.
In 2017, Swanson appeared in 11 games for the Lions before he was placed on injured reserve. Pro Football Focus has him rated as the No. 33 center out of 38 qualifying players.travis