Jurgen Klopp's biggest challenge at Liverpool four years on from taking over as manager is to keep setting new standards, says long-time assistant Peter Krawietz.

Tuesday marks the fourth anniversary of Klopp's appointment at Anfield, with the German leading the Reds to Champions League glory and turning Liverpool in title contenders.

Liverpool have made a flawless start to the Premier League campaign, taking maximum points to open up an eight-point gap over defending champions Manchester City, who pipped Klopp's men by a solitary point last term.

Krawietz has been a mainstay of Klopp's backroom teams throughout his career, having linked up with the 52-year-old at Mainz and Borussia Dortmund.

He believes the key to Liverpool's success is fine tuning the smaller details and ensuring new standards are continuously set.

"It's always like this – teams who are successful will always be something like a role model," he told Liverpool's official website. 

"It's an honour. And a challenge as well, because the standards are set and in order to improve you have to go on, you have to keep the level high and always look at the little details. 

"For example, this season there are new rules about goal-kicks. With this, we have to think anew about the details and that keeps it interesting. We'll try to get better and keep the high level and standards."

Klopp has struck up a big affinity with Reds fans and the city of Liverpool during his reign, a factor Krawietz says is vital to their methods.

"We always felt something like an identity with the club we were working for. In Mainz, it was our hometown where we grew up – so obviously it was easy because it was natural," he added. 

"We found this in Dortmund pretty quickly. And it is, and was, the same here in Liverpool. The more you learn about this city, of course adapting a little bit, and learn how people think and what they expect…of course, it helps if you have a little bit of success! 

"Then people can see from the outside things are going forward. This is what we always wanted. We thought the things we want to invent take a bit of time – a long-term idea – and we'd come somewhere where we'd try to make an impact for the whole club, something that stays for longer even if you are not here anymore. 

"Something which stays – not only trophies and a good time – and that it can go on. It worked in Mainz, it worked in Dortmund and I hope we are in a good way to do it as well in Liverpool."