The Spanish defender was speaking after compatriot Luis Enrique announced he was leaving the club following a disappointing season as coach.
"It is pleasing to know that you are of interest to a team like Barcelona," Angel told Com Radio. "They are one of the strongest teams in the world.
"There was contact with Barcelona and Sporting Lisbon last summer, but no agreement was ever reached.
"You can’t say no to Barcelona."
Angel, 22, joined Roma from Sporting Gijon last summer. He made 21 Serie A appearances as Roma finished seventh.
Barca are short of options at left-back following Eric Abidal's liver transplant.
Currently Adriano Correia is the only senior player in that position, and Angel would be a much cheaper option than Tottenham winger Gareth Bale, who has been linked with a move to the Camp Nou and can also play at full-back.