The 20-year-old has made his first three Primeira Liga appearances this season, coming off the bench each time, and has scored one goal and tallied two assists.
Sporting are reportedly trying to ward off Barcelona’s interest by agreeing a new deal with the youngster, which will include a €45 million release clause.
Cabral is a Cape Verde international, having made one national team appearance last year.
“It’s a great source of pride to be captain of this team,” said Messi, who has been at the club since he was 13, rising through the ranks at La Masia and then on to the first team.
The 31-year-old was named skipper this summer after club legend Andres Iniesta departed for Japanese club Vissel Kobe, following his own successful 16-year spell in the famous Blaugrana shirt.
Messi has made 641 appearances for Barca, scoring an incredible 556 goals.
Barcelona winger Malcom is expected to miss a week after suffering an ankle sprain in training on Monday, the club revealed.
The 21-year-old arrived from Bordeaux in a dramatic transfer this summer after Barcelona hijacked a move to Roma that had already been agreed.
Malcom made one appearance this season, coming on as a late substitute during the club’s 1-0 win over Real Valladolid in the second fixture of the league campaign.
The Brazilian was not named in his national team’s squad for their upcoming friendlies during the ongoing international break, thus staying back in Catalonia to train.