Jets center Nick Mangold has expressed frustration over the team's unwillingness to negotiate a contract extension, but he's not planning a training-camp holdout. "It doesn't seem to me to do any good to do it, so I'll be there with bells on," Mangold told the NFL Network. New York will open camp on Aug. 1st. Mangold, an All-Pro, is entering the final year of a five-year contact, due to make $3.3 million.