Petrus, a 2010 fifth-round pick of the Giants, was released by New York on Nov. 3. He has played in 23 games with three starts during his career. It's possible that the Patriots are exploring depth options along the interior of the offensive line after both of their starting guards, Dan Connolly and Logan Mankins, left Sunday's game due to injury.
Cartwright, 32, was a seventh-round pick of the Redskins in 2002 and has spent time with the Redskins, Raiders and most recently the 49ers. He is known for his strong special teams ability and also has 228 career carries for 956 yards and six touchdowns.
In addition, the Patriots worked out wide receiver Kamar Aiken, who recently was released from the Bears' practice squad, and wide receiver Lavasier Tuinei, a rookie wide receiver recently released from the Seahawks' practice squad.