The 27-year-old right-hander, originally included in Friday's seven-player trade that sent right-hander Andrew Cashner to the Marlins, was dealt back to San Diego on Monday in exchange for right-handed prospect Luis Castillo -- who initially came to the Padres from Miami in that deal.
Rea exited his start on Saturday with an elbow injury. A Padres source said "it's in the best interest of everyone" that the second trade go through. The Padres were adamant that Rea was fully healthy at the time of the deal.
The source pointed to the fact that the Padres weren't even shopping Rea until the Marlins asked about him.