The Arsenal Supporters Trust has spoken of its delight after the Gunners announced the arrival of Mesut Ozil from Real Madrid for £42.5m.
However, despite hailing the signing as "transformational" they have urged the Arsenal board to restructure their recruitment policy in time for the next transfer window.
Arsenal confirmed the signing of Ozil late last night after also sealing a year-long loan deal for Italian goalkeeper Emiliano Viviano from Palermo.
The signing of German star Ozil blew Arsenal's previous transfer record of £15m out the window, showing the football world that they are no longer held by the financial constraints that came with the move to the Emirates stadium.
But the deal only masks over what had otherwise been a very disappointing window for Arsene Wenger.
The manager had missed out on targets such as Luis Suarez and Gonzalo Higuain, ultimately leaving £50m of Arsenal's transfer budget unused.
It read: “We welcome the statement of intent Arsenal have made with the signing of a world-class player like Mesut Ozil. It is a transformational signing for the club in terms of both transfer fee and wages paid.
"It is, however, frustrating that once again a window has closed with over £50m left unspent. The AST would like to see all available resources put toward strengthening the team.
Although delighted, the AST, who own around 4.5% of Arsenal, have called on the board to be more proactive in future windows and not leaving deals so late.
Arsenal's interest in Ozil came so late in the window that Real Madrid refused to enter discussion before Gareth Bale's deal was completed.
That ultimately left the transfer in some doubt on the final day and the AST does not want a repeat of that situation.
The statement read: “This summer’s transfer window has also reinforced the AST’s view that the club need to overhaul their boardroom and football management infrastructure so they have the very best set-up to maximise the way in which the modern-day transfer window now operates.”