SANTA CLARA, Calif. (AP) - The San Francisco 49ers have signed defensive lineman Arik Armstead to a five-year contract worth up to $85 million to keep him off the free agent market. A person familiar with the deal says on condition of anonymity that the team then traded defensive tackle DeForest Buckner to Indianapolis for the No. 13 overall pick in this year's draft. The person says Buckner will get a new contract worth an average of $21 million a year. The trade and contract can't be official until the start of the new league year.