Wenger defends lack of transfers, questions Man United's Anthony Martial buy

Arsenal's lack of summer transfer activity has irked many of its fans, provoking a registered group called the Arsenal Supporters' Trust (AST) to question the club's practices via a formal inquiry.

The AST's statement included the following:

This isn't an issue that affects just one transfer window and seems to indicate a wider structural issue. In recent years Arsenal have overhauled both their Academy and their medical set-up. We urge the board to now open a full review into its arrangements for scouting and purchasing players.

Related: Arsenal Supporters' Trust express displeasure with the club's frugal practices

The North London outfit was the only club in Europe's top five divisions not to sign a first-team outfield player in the window, but manager Arsene Wenger has defended the club's transfer policy.

He told beIN Sports via the Guardian: "Am I happy with the investment I make? Yes, every time. I bought (Alexis) Sanchez, I bought (Mesut) Ozil, I bought (Petr) Cech, I bought Gabriel last year ... "

Wenger has previously bemoaned the lack of top strikers available in the market this summer, and suggested that he would only buy players that would complement his starting eleven.

"When you have to invest you have to find the players to invest in ... The problem at the moment is finding the players that guarantee you are a better team afterwards."

This led the Frenchman to question Manchester United's acquisition of compatriot Anthony Martial. The 19-year-old could become the second-costliest signing in Premier League history after add-ons.

"What happened last night with Monaco, who sold Martial to Manchester United for €80 million (£58 million), I've heard ... Martial scored 11 goals in the French championship - that sums it up well."

For Wenger, it was a transfer that smacked of desperation.

"That means it's not the money that's missing at the moment, it's not the desire of investment that is missing, it's the number of players available who can strengthen the big clubs.”

Arsenal should again start with its sole signing of the summer, goalkeeper Petr Cech, when it hosts Stoke City on September 12.