Liverpool paid a then-world-record £75 million to sign Van Dijk from Southampton, and he has gone on to make a huge impression at Anfield.
Speaking to ESPN's Melissa Reddy, Van Dijk said Henderson "painted the picture for me and made it easy to join." The Dutchman also described the midfielder as an "important factor" in his decision to move to Liverpool.
Van Dijk came close to joining the Reds in the summer of 2017, and the defender said the interactions he had with supporters following the failed move increased his desire to join:
"That summer when I made the decision until I actually joined the club, I had so many Liverpool fans coming up to me wherever I went—everywhere—telling me how much they wanted me to sign for the club.
"That gave me a bit of a feeling of how big Liverpool is and how passionate the supporters are. When you look at the Barcelona game [in last season's Champions League semi-finals], the scenes from the parade in the city and you watch videos of them celebrating all over the world, it says everything. It's unbelievable to be involved in something so special."
Van Dijk is one of the main reasons that Liverpool supporters have had success to celebrate as of late.
He has developed into one of the best centre-backs in world football, providing a dominant presence at the base of the Liverpool side.
Van Dijk is physical, composed and has natural defensive instincts; it means he's an extremely difficult defender for opposition forwards to get past:
Van Dijk is also capable of having an impact in the opposition box. The defender was key in Liverpool's equaliser against Manchester City in the Community Shield on Sunday:
Henderson has developed as a captain in recent years for Liverpool, and his influence was clear on the side as they challenged for major titles in latter stages of the 2018-19 season.
The midfielder was given more license to attack by Klopp in the second half of the campaign, and he responded with some dynamic displays at the hub of the team.
Van Dijk has had glowing praise for the 29-year-old in the past, too:
The signing of Van Dijk was followed by a busy summer for Liverpool, as they moved for Fabinho, Alisson Becker, Naby Keita and Xherdan Shaqiri in a transfer window of major spending. As of yet, manager Jurgen Klopp has not bolstered his squad with any senior players in 2019.
Even so, with Van Dijk a force of nature in defence for Liverpool, the foundations are there for the team to enjoy another memorable campaign. Based on Sunday's 1-1 draw between the Reds and City, which the latter eventually won via a penalty shootout, the two sides are evenly matched again going into the new season.