Jurgen Klopp is winning over Dietmar Hamann but the former Liverpool midfielder still thinks his fellow German cannot be considered a success at Anfield until he wins a trophy.
Hamann questioned the "tactical nous" of Klopp's Liverpool after the 2016-17 season, when they edged Arsenal to the final Champions League qualification spot after losing in the Carabao Cup semi-finals against Southampton.
The Reds look nailed on to finish in the top four this season, with the chance of taking second still a possibility, and head into Tuesday's Champions League quarter-final second leg against Manchester City with a 3-0 advantage.
Liverpool's consistency has impressed Hamann, who, speaking at an event organised by One Family and the Ian Rush Foundation, offered a more positive review of Klopp's work.
He told Omnisport: "There have been changes to a certain extent. They've shown consistency.
"It's all well and good to say we beat City, Chelsea away. All that matters is where you're at at end of season. More often than not that's been disappointing in recent years.
"I feel for first time there's a level of consistency in the team and the club. I think you have something to build on, trophies can be won: League Cups, FA Cup titles, the Champions League.
"Liverpool is about winning. [Not] just simply saying, 'We're improving, progressing.' I think team and manager have to win trophies. This is most confident I have been in number of years.
"The team's moving forward, progressing, but to go the last step is always hardest. They've had chances, semi-final a few years ago, so I am optimistic and slightly changed my mind [about Klopp] but until he wins trophies I don't think he can ever say he's arrived at Liverpool."
Following their 3-0 defeat at Anfield, City missed a chance to wrap up the Premier League title against arch-rivals Manchester United on Saturday by letting a two-goal lead slip for a 3-2 loss.
It would take an almighty capitulation to stop Pep Guardiola completing a domestic double after their Carabao Cup success, with Hamann impressed by how quickly he has instilled his philosophy at the Etihad Stadium.
"I think it surprised me how quickly he got his message through. I didn't think the football he played at Barcelona or Bayern [Munich] was possible in the Premier League," said Hamann.
"But if you look at the players he's bought and had, the improvements they've mad; Kevin De Bruyne, Leroy Sane who was good but now top, if you look at Raheem Sterling who has always been a good player but even he is on another level.
"The way he did it and how quickly, I wasn't surprised but a lot quicker than I expected."