The Miami Marlins have two games remaining on their six-game Southern California road trip against the Los Angeles Dodgers. After that, they will fly cross-country back to South Florida for a homestand that begins with a visit from the Philadelphia Phillies. Surprisingly, the Phillies and New York Mets are bringing up the rear in the National League East with identical 9-19 records. They are the two biggest underachievers in MLB so far this season. On Saturday night, the Boston Red Sox made the stunning decision to fire manager Alex Cora. On Tuesday, the Phillies did the same with Rob Thomson after just 28 games. Don Mattingly was named the interim manager for the rest of the season and his second series will be in Miami. Marlins to Face Former Manager Don Mattingly This Weekend Don Mattingly | Jim Rassol-Imagn Images When Philadelphia general manager Dave Dombrowski made the decision to fire Thomson, he replaced him with Mattingly.…