The promising youngster has picked up a hamstring problem and will be out of action for an estimated four weeks
The youngster featured from the start against Cordoba in the Copa del Rey on Wednesday, but was forced to leave the pitch shortly after the interval due to a hamstring problem.
Roberto underwent further examination immediately after the match, and the Blaugrana have now confirmed on their official website that the midfielder has suffered a tear in his left hamstring, and will consequently be out of action for four weeks.
The 20-year-old is seen as one of the club's most promising prospects and has made four official appearances for the Catalans this term.
Barca resume La Liga duties on Sunday when they travel to Malaga.