The production of the upcoming show has been delayed while his role is being recast, reported Us magazine.
According to a source the 39-year-old "True Blood" alum will not face any issues as it is a manageable preexisting condition.
The eight-episode scripted military drama follows a Navy SEAL Team 'Six' mission to eliminate a Taliban leader. Manganiello was set to play squad's leader, Rip Taggart.
"Six" also stars "Revenge" actor Barry Sloane, Dominic Adams, Edwin Hodge, Kyle Schmidt and Juan Pablo Raba.