The Marlins and Padres made the strangest 'trade' on deadline day

The Miami Marlins and San Diego Padres made a deal before the MLB trade deadline struck on Monday that probably won't be talked about much, but it was definitely the strangest deal of the day.

Miami shipped a player back to San Diego only three days after originally trading for him. Here's what happened:

Last Friday, the teams made a seven-player deal. The Marlins got pitchers Andrew Cashner and Colin Rea, plus pitching prospect Tayron Guerrero, and the Padres received pitchers Jarred Cosart and Carter Capps, plus two minor leagues -- pitcher Luis Castillo and first baseman Josh Naylor.

On Saturday, Rea made his first start for the Marlins and left with an injury in the fourth inning and then went on the 15-day DL a day later with an elbow sprain. Horrible luck for the Marlins, right? Well:

Source: #Marlins sending Rea back to #Padres but keeping Cashner. Rea left first start with MIA due to elbow injury.
— Ken Rosenthal (@Ken_Rosenthal) August 1, 2016

Source: #Marlins getting Luis Castillo back, with Rea returning to #Padres.
— Ken Rosenthal (@Ken_Rosenthal) August 1, 2016

I'm not sure if there's an unspoken trade etiquette between teams that reopens deals if a player gets injured immediately after trading for him, but the Marlins were able to trade Rea back to San Diego three days after getting him. So the final trade comes out to this:

Marlins get: Andrew Cashner, Tayron Guerrero and 3.1 scoreless innings from Colin Rea.

Padres get: Jarred Cosart, Carter Capps, Josh Naylor.