He has become a stand-out figure in Italy's Under-21 side, leading them to the European Championship Final against Spain.
"Congratulations to Lorenzo Insigne, one of the key players in the Italian Under-21 national team," read the statement on Benitez's official website.
"You are now playing at another level. Hopefully you can maintain this momentum in the upcoming season and I look forward to meeting up with you in a few weeks. Regards."