Mets GM Sandy Alderson announced Monday that Backman is leaving the organization to pursue other opportunities.
Backman said on Twitter that he resigned, however multiple reports indicate he was fired.
According to the Bergen Record reporter Bob Klapisch, Backman may have resigned in advance of being fired.
"I'll have something to say about this. Very soon," Backman told Klapisch.
Disagreements between Backman and Alderson often ranged from the distribution of playing time to lineup construction, sources told Newsday's David Lennon.
For instance, according to the New York Post's Mike Puma, Backman refused to use outfielder Brandon Nimmo in the leadoff spot and kept Michael Conforto on the bench against left-handed pitching.