Former Mainz forward Nicolai Muller says Loris Karius didn't move to Liverpool prematurely.

The talented young goalkeeper was loaned to Mainz from Manchester City in 2011, with the deal made permanent in January 2012.

He made his first-team debut on December 2012 but failed to make a significant breakthrough until the 2013/14 season, in which he would make 23 appearances across all competitions.

Karius' stock exploded from there, firmly setting himself as Mainz's first-choice goalkeeper over the 2014/15 and 2015/16 seasons.

His potential was recognised by Liverpool, who had a connection with Mainz through Jurgen Klopp, who played with club before managing them between 2001 to 2008.

The Premier League club signed Karius, then 22, in the summer of 2016 for £4.75m on a five-year deal.

The German displaced Simon Mignolet as Klopp's first-choice goalkeeper during the 2017/18 season, but two errors in the 2018 Champions League final loss to Real Madrid called into Karius' quality and maturity.

Asked if Karius joined Liverpool prematurely, Muller told Tribalfootball.com: "No I don't think so. He came from Manchester City to Mainz at 18 or 19. He needed a little bit of time.

"He got a chance in the first-team and did very, very well. And then when you have an offer from Liverpool, you have to do this. And why not?"

Liverpool immediately bolstered their goalkeeping stocks by signing Alisson Becker from Roma, and Karius was subsequently sent off to Besiktas on a two-year loan.

Given the success the Reds have achieved with the Brazilian as their goalkeeper, Muller says Karius can't have too many complaints.

"I think after the final they bought Alisson, then it is very difficult for Loris to play," the Western Sydney Wanderers forward added.

"But in the end Liverpool made the right decision because they have one of the best goalkeepers in the world and he saved a lot of games."