Jurgen Klopp is "not surprised at all" by Ilkay Gundogan's outstanding form for Manchester City, describing the midfielder as "one of the best players I ever coached".

Gundogan is enjoying the best scoring season of his league career, netting seven times to help City climb to the top of the Premier League.

Robbed of Sergio Aguero for an extended period and now also without Kevin De Bruyne, Pep Guardiola has handed additional attacking responsibilities to the Germany international, who is thriving.

Gundogan, a 2016 signing from Borussia Dortmund, has nine goals in all competitions this term at a rate of 0.5 per 90 minutes, his best performance in a City shirt.

Yet Gundogan continues to create for his team-mates, too, supplying a pair of assists and creating 1.8 chances per 90, trailing only his numbers for the 2018-19 season.

At Dortmund, where he played for several years under Klopp, Gundogan neither scored nor created at this rate across any single season, his highest return in terms of goal involvements the three goals and six assists in his final campaign.

Even as the 30-year-old outperforms his younger self, though, this is a standard Klopp expected Gundogan to set once he stayed fit for an extended period.

"Not at all [surprised] - the goalscoring maybe a little bit, the rest not," Klopp said ahead of facing City on Sunday "Ilkay was one of the best players I ever coached.

"He was a very young player when he came to us from Nurnberg to Dortmund. Especially in the 2012 season, he was unbelievable and played pretty much like he is playing now.

"Then he had, unfortunately, some injuries, really tough injuries, but that's now all sorted.

"It's the longest period he can play football without getting interrupted and I wish him really well that he can continue like this.

"That's the only reason. He was always that player.

"When you are smart and experience comes into play as well, then it's another jump in your performance level, and I'm not surprised at all."

Klopp was less interested in discussing the merits of Ruben Dias, a player he has never worked with but who has drawn comparisons with injured Liverpool defender Virgil van Dijk.

Dias debuted after the first two matches of the season, one of which City lost 5-2 at home to Leicester City, but has since formed part of a defence conceding 0.4 goals per game.

Klopp acknowledged Dias represented "good business" yet could not comment on an opponent he does not know personally.

Referring to Liverpool's defensive injury crisis, Klopp said: "That's a really harsh one. You talk about a centre-half... that's not nice.

"He had an impact, he's a good player, but City's a good team, to be honest, a really good team. They were always.

"It's good business, absolutely. Do I compare it with Virgil? You can compare him with Virgil; I don't know him good enough.

"Virgil is an outstanding football player, but I know him as a person, and the package makes for me the difference. I don't know anything about Ruben Dias. I'm sure he's a nice fellow, but I don't know it."