The Giants yesterday added to their roster for training camp by signing Kevin McMahan, a wide receiver from Maine who owns the dubious distinction of being known as Mr. Irrelevant as the last player taken in the 2006 NFL Draft.

McMahan, 24, was selected a year ago by the Raiders, who cut him prior to the season. McMahan has desirable size (6-2, 200) and speed (4.34), but he is coming off a hamstring injury that caused the Colts – who signed him last January – to release him.

With veteran Amani Toomer coming off a surgically repaired knee and limited to one practice per day and Plaxico Burress coming off clean-up ankle surgery, the Giants need numbers at receiver. Still, with the return from injury of Sinorice Moss and the drafting of Steve Smith in the second round, there are few roster spots available at receiver.

paul.schwartz@nypost.com