Jürgen Klopp often highlighted the importance of mental strength last season – and Dietmar Hamann has stressed just how crucial it will be to Liverpool's hopes of success.

In the opening months of his tenure, the manager spoke repeatedly about the need for players to retain belief and battle until the last second of every game, no matter the circumstances.

That resolve and spirit was evident in Klopp’s triumphant Borussia Dortmund side and could be observed in the Reds at times too, most notably when they recovered to eliminate the Bundesliga club in the Europa League quarter-finals.

Now they have to show it with greater regularity, according to Hamann.

“For a very long time in Germany nobody had managed to challenge Bayern Munich over a sustained period,” the 2005 Champions League winner writes in his latest column for the official Liverpool FC magazine.

“The odd club, such as Wolfsburg or Stuttgart, had matched them for a season, but that was it. Nobody could compete with them for a longer spell and the general consensus was that no team ever would. Bayern were too big, too powerful and just too good.

“Then Jürgen Klopp came along with Borussia Dortmund. He had the belief that his side could topple Munich and he instilled his players with this belief too.

“He made them so mentally strong that they became league champions two years in a row, cup winners and even Champions League finalists. They toppled Bayern to become the Bundesliga’s best.

“Right now Klopp is setting out to achieve something similar with Liverpool in the Premier League. Shortly after his appointment he told his players he wanted them to become mentally strong machines similar to those he had at Dortmund.

“That demand is understandable as, if the club are to achieve success over the coming years, Klopp knows his team will be tested. They’ll go into big games on a regular basis and it’s in those contests where they’ll need to be mentally strong.

“Those type of fixtures often see sides cancel each other out. So it can be the team who are mentally stronger that doesn’t make the vital mistake or just squeezes through to a semi-final or final. You need big personalities with the right character in order to get the job done.”