Qualquer que seja o processo que Hidra usou para presentear Bucky com as habilidades que ele tem em Capitão América: O Soldado Invernal já havia sido iniciado pelo Dr. Arnim Zola quando ele foi resgatado de seu laboratório na Base Hídrica da Áustria por Rogers em Capitão América: O Primeiro Vingador e foi continuado após sua aparente morte mais tarde no filme.
De "Wiki do universo cinemático da Marvel" :
Using S.H.I.E.L.D.'s resources, Zola continued his experiments on Bucky Barnes with other doctors to turn him into HYDRA's secret weapon/assassin. Zola also managed to build an entire computer system which his mind was uploaded into as an artificially intelligent user interface. Though Zola's body died in 1972, his mind continued to live in cyberspace, where he was able to provide easy passage into the agency for HYDRA sleeper agents that either managed to escape justice during the war or were corrupted from within.