The Patriots have signed offensive lineman Donald Thomas to the 53-man roster, the team announced Wednesday.

Thomas, a sixth-round draft pick out of UConn in 2008, played the last three seasons with the Dolphins and Lions. The 6-foot-4, 310-pound guard started 12 games in his second season with Miami in 2009, and spent most of his rookie season and 2010 inactive.

The Patriots released offensive lineman Thomas Welch, according to a news release.

The Patriots also released linebacker Aaron Lavarias from the practice squad and added tight end Garrett Mills and linebacker Jeff Tarpinian to the practice squad.