Comolli signed Henderson from Sunderland in 2011 for a reported £20m, and despite his initial struggles under former Liverpool boss Brendan Rodgers, Henderson has gone on to establish himself as one of the most important players in the side.
The 31-year-old has made 429 appearances for the Reds till date and went on to replace Steven Gerrard as club captain in 2015, and Comolli believes Henderson was instrumental in Liverpool winning their recent titles.
Speaking to So Foot magazine, he said: “I was even told that it was a huge mistake, but when you recruit a young player, you have to wait.
“Jordan was going to break through, that was for sure. [...] I can assure you that without him they won’t win the Champions League or the Premier League. I am 100 [per cent] convinced of it.”
Henderson, who is under contract with Liverpool until 2025, is yet to begin contract negotiations with the club, but boss Jurgen Klopp has insisted that he is “relaxed” over the situation surrounding Henderson’s Liverpool future.
“I know what’s going on behind the scenes and am relaxed,” the Liverpool manager told Sky Sports last October. “We don’t talk about these kinds of things and we cannot make exemptions for one specific case.
“The one thing I can say is nobody has to worry. Things will go their way and be handled like they should be. That’s all I can give you as news but if I’m relaxed about this, then you can imagine it’s going in the right direction.”