The Giants have beefed up the depth on their defensive line, signing unrestricted free agent tackle Marcus Bell, a six-year veteran, to a one-year contract. Coming off the most productive season of his career, Bell, 28, is expected to challenge for a role in the Giants' regular tackle rotation. Although he is more of a nose tackle, Bell has played at both tackle spots during his NFL tenure, and will add experience and versatility to the New York defensive line.