The San Diego Padres are trying to turn over their roster, but there aren't a lot of ways for them to dump significant salary. Matt Kemp almost certainly cannot be moved, nor can Melvin Upton Jr., and while rival officials have some interest in James Shields, many think that the $65 million he's owed over the next three years is too much and that the Padres would have to eat a significant portion of it to make a deal for the starting pitcher worthwhile.
This is why closer Craig Kimbrel continues to be a candidate to be traded in the next six days -- or maybe in August -- because he does have some value as one of the game's best closers, and the Padres have indicated a willingness to deal him.
But few teams are interested in paying more than $8-10 million annually for the best relievers, considering they contribute about a third of the innings that starting pitchers log and given how notoriously volatile bullpen performances can be.