The New England Patriots have signed offensive lineman Donald Thomas to bolster a unit that lost center Dan Koppen to an ankle injury.
Koppen is expected to miss 6 to 10 weeks, NFL Network's Albert Breer reported Tuesday, citing a league source. Koppen suffered the injury late in the first half of Monday night's season-opening 38-24 win at the Miami Dolphins.
In Wednesday's other moves, the Patriots released offensive lineman Thomas Welch, signed tight end Garrett Mills and linebacker Jeff Tarpinian to the practice squad and released linebacker Aaron Lavarias from the practice squad.
The Associated Press contributed to this report.