The Marlins are mulling over the possibility of making a run at Giants infielder Mark DeRosa. Last weekend, Ken Rosenthal of FOX Sports wrote that DeRosa would be a perfect fit for the Marlins. Florida has used four different players at fourth already this season. DeRosa is entering the final year of a two-year, $12 million contract. If the Marlins acquired him on May 15, he would cost them about $4.5 million through season's end.