A gas turbine engine is provided and includes a combustor having a first interior in which a first fuel is combustible, the first fuel including natural gas and/or a blend of natural gas and alternate gas receivable by a fuel circuit from an external source, a turbine, a transition zone, including a second interior in which a second fuel, the second fuel including an unblended supply of the alternate gas receivable by the fuel circuit from the external source, and the products of the combustion of the first fuel are combustible, and a plurality of fuel injectors, which are structurally supported by the transition zone and coupled to the fuel circuit, and which are configured to supply the second fuel to the second interior in any one of a single axial stage, multiple axial stages, a single axial circumferential stage and multiple axial circumferential stages.