The Marlins are continuing their search for a pitching coordinator and field coordinator.
Andy Barkett, a hitting coordinator for the Marlins this season, is a candidate to be promoted to the big leagues as an assistant hitting coach.
Dillon, 40, a former utility player, broke into the big leagues with the Marlins in 2005 after being a seventh-round pick of the Royals in 1997. He also played for the Brewers and Rays, with his last big league season being 2009.
Dillon was a hitting coach in the Minors for the Nationals.
Cathcart, 52, was a 33rd-round pick of the Yankees in 1984. He has managing experience in the Nationals' system.
The Marlins recently announced the hiring of Marc DelPiano as vice president of player development to oversee the Minor League system.
Highly respected, DelPiano was in the Marlins' organization when they won the World Series in 2003 and rejoined Miami after being a special assistant with the Pirates.