Giants reserve linebacker Spencer Paysinger left Sunday's game against Green Bay with a hamstring injury.
The team says he will not return.
Paysinger has been a regular contributor to special teams this year.
Due to a rash of injuries at linebacker, Paysinger has also played snaps on defense in recent games.
Paysinger has nine tackles on the season.
With rookie Mark Herzlich out with an ankle injury, the Giants depth at linebacker is thin. Middle linebacker Michael Boley returned to the field for the first time on Sunday after missing two weeks with a hamstring injury.
Greg Jones is backing up Boley at middle linebacker.