The Giants confirmed the signing late Tuesday night and announced they had waived tight end Jake Ballard.
New York lost star receiver Steve Smith to a partial tear in his pectoral muscle on Nov. 11 and backup Ramses Barden to a broken ankle three days later. Leading receiver Hakeem Nicks is going to be sidelined about three weeks after needing a surgical procedure on Monday to relieve pressure in his right leg. He was hurt Sunday against Philadelphia.
Clayton has been playing for Omaha in the United Football League. He had 16 catches in 13 games with the Bucs last season.
Ballard was signed off the Giants' practice squad late last week.