Sullivan, 33, is a former sixth-round pick of the Vikings back in 2008. He had two years remaining on his six-year, $25.6 million contract when the Vikings cut him loose in 2016 after they were unable to find a trade partner.
The Redskins signed him to a contract a few weeks into the regular season and finished out the 2016 season in Washington. Sullivan joined the Rams for the 2017 season and returned to the team on a two-year contract last year.
According to OverTheCap.com, this move will free up $5.25 million of available cap space while creating $1 million in dead money.
In 2018, Sullivan appeared in all 16 games for the Rams and Pro Football Focus graded him as the No. 31 overall center out of 38 qualifiers.