The Japanese star left Liverpool and joined Monaco in a £15.5million deal, just two-and-a-half years after signing.
He made 55 appearances during his time at Anfield, but leaves with three trophies to his name - the Premier League, FA Cup and League Cup.
Despite his relatively short time with the club, which also included a loan spell at Southampton, he was a popular member of the squad.
Manager Jurgen Klopp said: "An amazing professional; super, talented player. As a person, he is full of warmth and makes everyone feel positive. A manager's dream, to be honest."
And Henderson sent a kind message on Instagram saying thank you to the Japan star.
It is not the first time that the Liverpool captain has gone out of his way to make Minamino feel welcome.
He made sure the Reds fans gave the 27-year-old a rapturous reception when he lifted the Carabao Cup trophy at Wembley earlier this year.
Minamino did not get on the pitch in the final, but was influential in their run to the trophy, scoring four times.
Henderson has a habit of making sure his teammates get their chance to lift the trophies they win and have photos taken.
When Liverpool won the Premier League title in 2020, the England international was there again to make sure Minamino was included.
When he saw his teammate was on the outskirts of the celebrations, he dragged him in to make sure he held the trophy.