Real Madrid added Castilla players Mariano Diaz and Philipp Lienhart to their Champions League squad ahead of the knockout stage.
Roma host Real Madrid in the first leg of their round-of-16 tie on Wednesday.
Diaz, 22, has scored 13 goals for the club's reserve team this season. Last month, he sealed a first-team contract that begins next season.
Centre-back Lienhart, 19, made his first-team debut in December as a substitute against Cadiz in the Copa del Rey.
They replace Denis Cheryshev,...