I don't know where you get your rumors from, but no one I know with even a minimum of knowledge of the situation is speaking of a Manning trade.
There will be no trade. If you want to be "realistic", you need to cut Manning and let him go to Free Agency, cause that's what's gonna happen in reality.
There was never a way for Manning to be traded, the Colts would need to pay him a crapload of money (more than 20 million) as a bonus before the start of free agency, and there's no way whatsoever any NFL franchise pays a player that much just to trade him (because while in Madden, the money just magically appears out of thin air for you to spend as much as you want as long as you stay under the cap, in reality, that's REAL money, no GM is gonna just throw more than 20 million out the window)
So the only way for the Colts to trade Manning would be for him to rework his contract, but what reason could there be for him to do that? He knows the team wants him out, anyway, so why should he care whether they get a draft pick in return, and it would just limit his options because not every team would be ready to give up draft picks for him, so getting cut would be the much better option for Manning.