Contract details were not immediately available, but it is believed that Holsey will earn a base salary of $660,000.
A seven-year veteran, Holsey has played mostly at tackle during his career, but can line up at end as well, and his addition provides St. Louis some flexibility. It would seem that the Rams' greater need is at end, where they lost starter Grant Wistrom in free agency and where Pro Bowl performer Leonard Little faces felony charges based on an April arrest for alleged drunk driving, but landing Holsey could enable coaches to shuffle one of their tackles to the outside spot.
Holsey, 30, was one of the better players remaining in a diluted unrestricted pool and it was somewhat surprising, even given the journeyman nature of his career, that he went largely ignored until now. Holsey's representatives spoke with the Atlanta Falcons early in the signing period but nothing developed.
An undrafted free agent from Duke, Holsey entered the league with the New York Giants in 1996. His resume includes stints with the Giants (1996-99), Colts (2000), Patriots (2002) and Redskins (2003). He sat out the 2001 season.
For his career, Holsey has 182 tackles, 8½ sacks, one forced fumble and one recovery. He led Redskins defensive linemen last year with 41 tackles.
The Rams made another roster move Friday, releasing second-year safety Shane Walton, a fifth-round draft choice in 2003. Walton played in only four games as a rookie.
Len Pasquarelli is a senior writer for ESPN.com.