Redskins officials are picking up free agent running back Larry Johnson at the airport this afternoon, according to team sources, and they are very much interested in signing him. Redskins running back Clinton Portis visited a concussion specialist in Pittsburgh last week and was cleared to begin offseason activities with the team, according to a source, but the team hopes to sign Johnson. The ex-Chiefs and Bengals running back also has scheduled a Monday visit with the Raiders, according to a league source.