If the NFL lockout remains unresolved when this month's draft takes place, teams won't be able to trade picks after they've been used. In 2004, the Chargers took Eli Manning first overall and watched the Giants select Philip Rivers with the fourth pick. Eventually, the players swapped jerseys. "The Manning-Rivers type of trade cannot happen this year due to the lockout rules," NFL spokesman Greg Aiello told Pro Football Talk. "A trade at this time can involve only draft picks. Once a pick is made, the player cannot be traded (or signed) until a new league start begins. No player transactions are currently permitted."