All i can tell you is that trinidad didnt fight mosely..
Due to the following..

choices for his comeback fight..At Middleweight of course
De la Hoya - Knocked out by bernard hopkins
Mosely - Lost twice to winky wright

So he signed to fight mayorga, Who just beat forrest twice and lost a controversial decision to spinks and had failed to make weight last fight..So they signed him to fight at middleweight..

And because de la hoya didnt fight for a while after the loss to hopkins and it was winky wright who beat mosely he then signed to fight winky wright