The Patriots signed OG Mitch Petrus on Tuesday, the team announced.
Petrus, a fourth-year pro, played in six games for the Giants earlier this season before being released on Nov. 3. He has played in 23 NFL games with three starts at left guard since joining the league as a fifth-round pick by the Giants in 2010.
Patriots starting OGs Logan Mankins and Dan Connolly were both injured in Sunday's game against the Bills.
LB Jeff Tarpinian was re-signed to the Patriots' practice squad after being released on Monday.