LONDON. Manchester City have bought into new manager Manuel Pellegrini’s attacking philosophy, but with no defenders signed yet their assault on the Premier League title may well be scuppered by goals leaking at the other end.City’s back line has looked vulnerable in the close season and they go into their first match at home to Newcastle United on Monday having let in eight goals in their last three warm-up matches, including a 3-1 defeat by Arsenal on Saturday.This after boasting the meanest defence in the league last season when they let in 34 goals in 38 games in finishing runners-up to neighbours Manchester United.In the previous season they had an even better record, conceding just 29 on their way to the title.Having spent around £90 million on forwards Alvaro Negredo and Stevan Jovetic, winger Jesus Navas and midfielder Fernandinho in the close season, it is not surprising they have also scored seven times in those games.The trouble is that more goals conceded than netted does not add up to silverware, a challenge for a club whose chief executive has set a target of five trophies in the next five years.There is still time before the transfer window closes at the end of the month for the wealthy club to bolster their defence but even if they do, they seem to have made it clear where their priorities lie.Pellegrini, who replaced the sacked Roberto Mancini in June, has promised to instil an attractive brand of attacking football in his team but also knows this cannot be at the expense of City’s recent strengths."We had problems defending and we will try to improve this week,” local media quoted the Chilean as saying."If we buy someone, then OK. But, otherwise, we have a good squad. But, yes, we have conceded many goals, we will have to find ways to change this."You are always concerned when you are 3-0 down but we lost in pre-season. We did not lose three points and that is important. We will be at our best for the Premier League.”