To make room on their roster, the Giants waived defensive tackle Rodney Leisle.
The Super Bowl champions lost seven-time Pro Bowler Michael Strahan to retirement in June. Then two-time Pro Bowler Osi Umenyiora was sidelined with a season-ending knee injury a little more than a week ago.
A first round pick in 2003, McDougle was cut by Philadelphia on Saturday. He played in 33 games in five seasons and had three sacks.
He missed all of last season with a triceps injury and was out for all of 2005 after being shot in the abdomen during a robbery during the offseason.