Pep Guardiola has hailed the blossoming centre-back partnership between Nicolas Otamendi and John Stones at Manchester City, with Vincent Kompany's latest injury ordeal showing no sign of an upturn.

Guardiola told a news conference ahead of Saturday's game against Burnley that club captain Kompany would miss out once more with a calf problem and he had no idea when the Belgium defender would return.

Over recent seasons, Kompany's absences have tended to prompt varying degrees of collapse in form by City's backline.

But Otamendi and Stones have formed an increasingly assured alliance over the course of five Premier League victories and three out of three in the Champions League since Kompany last featured at Bournemouth in August.

"A lot, a lot – I'm really impressed," Guardiola said when reviewing the duo's form, reserving particular praise for Otamendi – a robust, no-frills defender who would not necessarily be expected to flourish under the former Barcelona and Bayern Munich boss.

"Always we talk about the guys who play offensively but John and Nico, both of them were fantastic in the last month because they played all the games.

"Nico played against Stoke City when I had a lot of doubts because he came from [international duty with] Argentina, from 10 days with a lot of pressure in his mind to qualify for the World Cup.

"He is one of the players I have met in my life with the strongest mentality and he is a guy who only wants to learn in terms of the ball possession.

"Always he was strong in the air and winning duels. Also, he has the courage to play. Even when he makes mistakes, it doesn’t matter. If he loses the ball, he wants you to give it to him again and play.

"He's not afraid at all, it doesn't matter where he plays, has a lot of experience. He is an important guy for us. All the season, he has played outstanding."

It is a far cry from the error strewn displays ex-Valencia man Otamendi and Stones – a £47million signing from Everton – turned in last season.

Then, Stones often found a champion in his manager when his willingness to build attacks from the back played himself and City into trouble.

As the Premier League leaders continue to click through the gears at the other end of the pitch, with 39 goals in all competitions, the fact that the 23-year-old is no longer a regular discussion topic speaks volumes for Guardiola.

"John, last year, every game it was always one or two mistakes with the ball and [he was] always distracted," Guardiola said, his defence having only been breached four times in the league.

"This season he is always focusing with the ball. I know his quality but he is improving."

The character shown by his centre-backs is something Guardiola knows his side will need in order to maintain the early purpose of their bid for glory.

In 2016-17, City won their first 10 matches at home and abroad before hitting trouble in October. By the turn of the year, they had faded from the title picture.

Guardiola was heartened by his players' response under pressure as they ground out a 2-1 win over Napoli in midweek but expects the biggest test of a team ever more in tune with his methods will come whenever their blistering early run is derailed.

"That is going to happen," he insisted. "We cannot expect, now we are in October, to finish the season how we started and in the last month when we won all the games.

"That is impossible in football at the high level. But I want to see that, I want to see how we are going to react in that moment when we drop points, how strong we are.

"The big teams always show in the bad moments. When we are winning by three or four it is important but it doesn’t count too much. In the bad moments, it counts how we react."