Pep Guardiola has warned Manchester City’s players that complacency could be their downfall if they presume the club’s success will last forever because such attitudes have cost others in the past. City face Manchester United in the FA Cup final on Saturday with the aim of becoming the first club in history to do the league and FA Cup Double in consecutive seasons. If City defeat their most bitter rivals at Wembley it would be the 18th trophy of Guardiola’s eight-year tenure. In the same period United have won three. “Many good teams thought in the past that it [winning] is taken for granted and look now, it’s difficult,” Guardiola said. “Always I say to the players to look at what they have done; always arriving in the finals is difficult. I don’t change my mind. “It’s so difficult to win [in previous rounds] at Spurs away, against Newcastle at home, Luton when they were in their good moment. To arrive here is difficult – I don’t take it for granted. This is the reason why. We respect the opponents a lot, know we can easily lose every game and at the same time we can win it. I’ve never had the feeling that it doesn’t matter, absolutely not. The finals, when you arrive, is: ‘Wow, what a privilege to be here again.’ People think: ‘Ah, it’s City, it’s what they have done for the last decade.’” Guardiola will go head-to-head with Erik ten Hag, who United have decided to sack regardless of the result. United finished eighth in the league and defeat by City would mean they will not play European football next season. “In big clubs like United, City, when you don’t win always you are in trouble,” Guardiola said. “I would be in trouble if we didn’t win. He [Ten Hag] has done many good things. I have huge respect for his job in the past and now at United I completely agree when I listen to him when he says they have not had a full squad this season and had a lot of injuries. “I think this is the most important thing they have to think about because I am always focused that we have to be fit, fit, fit – otherwise we cannot use the players. They had a lot of problems and when that happens the manager suffers a lot. The squad is really good but the problem is when you cannot use them. This is a big disadvantage.”