The 36-year-old, who has spent the 2019-10 campaign working alongside Alisson, told LFCTV: “Me and Kirky [Chris Kirkland] speak about him with other goalkeepers and I say ‘However good you think he is, he is better than that’.
“You watch him on a Saturday or in the Champions League and you think he is brilliant, but there’s just so much more to it than that. He’s technically the best.
“Everything he does is the best but his mentality and his sort of calmness… I can’t put into words how good he is. It’s just a joy to be part of the squad that he’s involved in.”
Alisson is currently waiting on a return to competitive action amid the coronavirus pandemic.
Liverpool are in training once more, with all medical advice being followed, and Lonergan is enjoying being back at work after a period of enforced rest.
He added: “It’s been brilliant. It’s obviously strange with the procedures that you have to go through to get on to the training pitch, but once you are on the pitch as goalkeepers you are working at a distance and it’s safe enough anyway so it’s back to normal. No settling in period, just straight into it.
“There is me and Alisson and the two goalkeeper coaches on one pitch, four or five on the other and the other half of the squad come in an hour or two later.
“When everything has been cleaned up and disinfected, then they come in so that’s how it’s working at the moment.”