A turbofan engine assembly includes a core gas turbine engine including a high-pressure compressor, a combustor, and a high-pressure turbine, a first fan assembly disposed upstream from the core gas turbine engine, a first gearbox coupled to the first fan assembly, and a second gearbox coupled to a booster compressor such that the booster compressor rotates in a rotational direction that is opposite to the rotational direction of the first fan assembly. A method of assembling the above turbofan engine assembly is also described herein.