Marshall has not signed his one-year, $1.759 million tender as a restricted free agent. He can't be fined for missing the mandatory minicamp since he's not under contract.
Marshall is one of many NFL players with four years experience who would've been unrestricted free agents if owners hadn't decided to opt out of collective bargaining agreement early and play without a salary cap this season. That put into effect new rules that require six years of service.
Coach John Fox says he's been assured that Marshall is staying in shape.
Agent Drew Rosenhaus didn't immediately return a phone message seeking comment on Friday.