Roberto Mancini airs his frustrations at Manchester City's lack of transfer activity

Manager's working relationship with executive Marwood strained by club's failure to make any new signings

'This year will not be easy,' admits the Mancester City manager, Roberto Mancini (EPA)

Roberto Mancini yesterday gave vent to his frustrations over Manchester City's lack of activity in the transfer market this summer, the latest indication of the struggle for influence and control at the top of the club between him and executive Brian Marwood.

Asked about absence of any signings, in the face of transfer activity from the likes of Manchester United, Chelsea and Arsenal, Mancini said that it was not his area of responsibility. "For this question, speak to the man in charge," he said. "I am not in charge of this. It is important [to sign players early] because, after what we did last year, it is important we continue to win."

Mancini and Marwood, the club's football administrator, have never enjoyed an easy working relationship, and this summer the latter has pursued a policy of getting those high-earning players frozen out by Mancini off the books first. There are also the imperatives of Uefa's Financial Fair Play rules, which must be taken into consideration.

Unfortunately for City, Emmanuel Adebayor, Roque Santa Cruz and Craig Bellamy are yet to be sold on, while Wayne Bridge is only on a subsidised, season-long loan to Brighton in the Championship. City face Arsenal in a friendly at the Beijing Olympic Stadium at 1pm, British time, today. Marwood has not travelled with the squad on their tour of the Far East.

Marwood's attitude this summer has been that the club must try to obtain some kind of fee for those players rather than paying up their contracts and allowing them to leave as free agents. For Mancini, who has no intention of bringing any of them back into the fold, that is a source of frustration as he attempts to make new signings, in particular up front.

However, there was good news yesterday for the club when they completed a new six-year deal with their captain, Vincent Kompany, an undoubted success story having arrived for a relatively cheap £6m from Hamburg in 2008. However, the resources that the league champions have put to use in the transfer market in the past have not been deployed this summer.

Mancini said: "This year will not be easy. It will be harder than last year and, for this reason, we need to improve our team. But I am not the man in charge of this. We have a man who works for this [Marwood] and we hope that they can do a good job."

The problem that City face in their pursuit of the Arsenal striker Robin van Persie is that the player regards the league champions as his third choice out of the three clubs pursuing him. His preference is for a move to Juventus, followed by Manchester United, and the only possible route that would take him to City would be if they outbid their rivals by some distance, forcing Arsenal to accept.

Even then City face another obstacle in Arsenal's manager, Arsène Wenger, who is reluctant to sell to any Premier League team. The club's board are of the opinion that they must cash in on Van Persie this summer rather than lose him for nothing in a year's time. However, if the player is of a mind to hold out for a move to either Juventus or United, he is likely to have the final say.

City have also made it clear to the football fraternity that they will not be paying the kind of £200,000-a-week-plus wages that were agreed with the likes of Yaya Touré, Carlos Tevez and Sergio Aguero, when the club had to use their financial power alone to attract top players. As Premier League champions and a Champions League team for the second year, City feel that they no longer have to pay such high wages to attract the top players.

Mancini said: "Van Persie is an Arsenal player, not our player. He is a fantastic player, but we have four strikers and with those strikers we won the title last year. Van Persie is a fantastic player, but he is an Arsenal player."

On signing his new deal, Kompany said: "I have been here since the beginning and I have seen everything at the club change inside and out. This Manchester City project was probably one of the most difficult in Europe and so far we have all done a good job even though a lot of people said it [success] wasn't going to happen so quickly. It is good to know that I can be at City for another six years. It is a compliment that the club feels so highly of me."