Hannibal started in Tunisia's opening game of the Arab Cup against Mauritania on Tuesday afternoon.
The midfielder provided an assist for his side's first goal just before half-time and Tunisia went on to win the game 5-1 in Qatar.
A total of 16 teams, divided into four groups, are taking part in the tournament and those teams include Qatar, Iraq, Oman, Bahrain, Tunisia, United Arab Emirates, Syria, Mauritania, Morocco, Saudi Arabia, Jordan, Palestine, Algeria, Egypt, Lebanon and Sudan.
Hannibal didn't feature in United's U23s' 2-1 defeat to Crystal Palace on Saturday as he had joined up with the Tunisian national team.
Neil Wood's side lost at Leigh Sports Village at the weekend and looked devoid of quality in the final third despite Anthony Elanga's involvement. Hannibal has played just five times in United's academy this season after recovering from injury.
The 19-year-old was named as the U23s Player of the Year last season and he made his senior debut against Wolves in May.
Hannibal only made his debut for Tunisia one month after that match in June, but he made the starting XI at the Arab Cup.
Hannibal has always been highly regarded in United's academy set-up since his arrival from Monaco in the summer of 2019 and the club tied him down to a new long-term contract earlier this year, which means his current deal expires in 2026.
