The 27-year-old right-hander asked a three-person panel Wednesday for a raise from $7.25 million to $10.4 million, and the Marlins argued he should be paid $9.4 million.
A decision by Margaret Brogan, Phillip LaPorte and Steven Wolf is likely Thursday.
Latos was 5-5 with a 3.25 ERA for Cincinnati in 16 starts last year, when he didn't pitch in the majors until June 14. He had surgery in October 2013 to remove bone spurs from his pitching elbow and another operation on Feb. 14 for torn cartilage in his left knee.
He made his last start on Sept. 7 because of a bone bruise in his right elbow. He was traded at the winter meetings to Miami for pitching prospect Anthony DeSclafani and minor league catcher Chad Wallach.
Latos is 60-45 with a 3.34 ERA over six seasons. He can become a free agent after this season.