Ronald Koeman has praised Everton’s resilient start to the season but admitted it may take a miraculous performance to keep another clean sheet at Manchester City on Monday.

Everton have not conceded in their first four competitive matches of this campaign having shut out Ruzomberok and Hajduk Split in the Europa League, plus Stoke City in the Premier League. Jordan Pickford and Michael Keane, the joint record signings until the £45m arrival of Gylfi Sigurdsson last week, have impressed in the new-look defence, moreover, but with City having also strengthened this summer, the Everton manager believes his players will face their sternest test so far at the Etihad Stadium.

Asked whether Pickford would find it easy to collect another clean sheet against Pep Guardiola’s team, Koeman replied: “If we get a clean sheet on Monday I don’t know if it will be a miracle. Maybe it will but we do know we are strong defensively, our defensive organisation is strong. The key to getting a good result is what we do when we have the ball and that’s what our preparation will be about. You have different ways to play, we will look at the best way to get a good result.”

Everton benefited from defensive and offensive approaches against City last season, securing a 1-1 draw at the Etihad, thanks to two penalty saves from Maarten Stekelenburg, and a 4-0 win at home, when punishing a chaotic City defence.

“I am a good friend of Pep and I know the way he likes to play,” said Koeman, a former room-mate of Guardiola’s at Barcelona. “It’s the most difficult way. It’s really a pleasure to see his teams playing football, with a high defence and a lot of offensive players in the team. But the Premier League sometimes is strong and physical, plus if you play with a high defence there is always space behind.

“When we played City at home we punished them for that but I think with the business they did in the summer City are stronger than last year.”

The Everton manager had claimed City were favourites for the 2016-17 Premier League title after October’s draw at the Etihad. By January, however, and the heaviest league defeat of his managerial career, Guardiola conceded at Goodison his team were out of the race. Koeman is wary of making a similar prediction this season.

He added: “When we played at City last season I mentioned that we were really lucky to get one point out of that game. On that day they played fantastic football and I spoke about them being the big favourites to win the league. After that they started to struggle but that’s football, you never know, it’s difficult to make predictions about who is the strongest. After the first weekend of this season, watching different teams, I was impressed by [Manchester] United, also impressed by City, but maybe in two weeks or two months it can be different. City are strong, of course they are strong.”

Everton took their summer spending past the £140m mark last week when completing the signing of Sigurdsson from Swansea. The Iceland midfielder is short of match fitness but will be involved in Everton’s demanding week of fixtures at City, Hajduk Split and Chelsea. Koeman believes his team require another striker but have the right balance following the summer’s investment.

“What you try to do is find a really good balance in your team of age and experience,” he added. “We brought a really young goalkeeper in Pickford and he is doing fantastic. Michael Keane can be one of the best central defenders in the Premier League and along with Sandro Ramírez and Davy Klaassen, we have brought in young players with a future, that is what you always need to find for balance.

“With Wayne and Gylfi it is about experience. Wayne Rooney, for example, won a lot of titles and that experience is really important for a team that wants to win titles.”

As a former United captain, Rooney will be guaranteed a hostile reception on his return to the blue side of Manchester but Koeman insisted: “He knows that stadium, it’s not the first time he has been there to play City.

“He might get a certain reception but he’s such an experienced player he’s not going to lose any sleep over it. He will like that platform to play football.”