Arsene Wenger
Wenger has stuck with his transfer policy. REUTERS

George Graham believes a top four finish in this season's Premier League would rank amongst Arsene Wenger's finest achievements at the club, because the Frenchman's reluctance to spend has had a negative impact on the Gunners' squad.

Arsenal and in particular their manager were derided by some of the Emirates crowd during their 2-1 defeat against Manchester United on Sunday.

The Frenchman, perhaps for the first time during his remarkable tenure was the subject of dissenting voices, and Graham fears Wenger's legacy at Arsenal could be sullied if the club fail to add more quality.

Wenger has been notoriously reluctant to enter the transfer market in order to find a quick fix for Arsenal over the years, yet Graham believes the current squad are lacking the necessary depth to last the rigours of a tough league campaign.

"You see somebody like Spurs and they've got so many players for all the positions," The former Arsenal manager told The London Evening Standard. "And you look at Arsenal - they've got to have their best team out to get into the top four.

"But if they've not got their best team I think the squad members who are coming in are just not quite good enough.

Like many of the club's evidently frustrated fans, Graham is confused as to why Arsenal are not investing more in top talent, suggesting some of Wenger's recent purchases have been less than impressive.

"There's plenty of revenue that should be coming into the club I can't understand why they're not getting a better class of player." Graham continued.

"Dennis Bergkamp, ­Robert Pires, Patrick Vieira, Thierry Henry, Marc Overmars, Freddie Ljungberg - if you don't replace those players with a similar ability, you are slowly going to slide away down the league.

"I hope that doesn't happen because Arsene's been fantastic for Arsenal and English football and I would hate to see that just slip away."

Graham suggests such is the current state of Arsenal's playing personnel, should Wenger successfully secure a top four finish this season then it would rank amongst one of the Frenchman's finest achievements at the club.

He added: "If they can get into the top four this season, that'll be one of his best accomplishments at the club."

The former Arsenal boss, who won two division league titles during his Highbury tenure, believes Wenger needs to spend and in particular invest heavily in finding a suitable alternative to the prolific Robin Van Persie.

"Robin Van Persie seems the only one to be scoring, unfortunately Theo Walcott on one side and Andrey Arshavin on the other are not filling in with their quota.

"I can see the point [of re-signing Henry], but Arsenal are so big they should have a bigger squad of players, especially in the forward positions.

"If you want a quality front player, you're talking big money, at least £20‑25million for a world-class striker to take the pressure off Van Persie.

"But will Arsenal give Arsene that money? Or have they got it? They've offered him the money but he won't spend it. No one seems to know the answer to that question."

Despite Wenger's increasingly numerous critics, who were patently premature in their forecasts in the aftermath of Arsenal's nadir at Old Trafford in August, the Gunners are still just five points behind fourth placed Chelsea, who have also had struggles of their own this season.