Arsene Wenger says Arsenal missed 'a fantastic opportunity' to win the league this season

Arsenal take on West Ham in the Premier League tonight

Arsenal walk out onto the pitch against Chelsea (GETTY IMAGES)

Arsene Wenger admits Arsenal have under-performed this season and missed a huge opportunity to end their nine-year wait for a Barclays Premier League title.

Wenger's early years at Arsenal were laden with success but the Gunners are no longer considered realistic title challengers and have not won a trophy of any kind in seven-and-a-half years.

The north London club welcome West Ham to the Emirates Stadium tonight knowing defeat will leave them seven points off fourth-placed Tottenham and some 22 behind their former arch-rivals and current league leaders Manchester United.

Despite their domination of the league, United have looked a pale imitation of Sir Alex Ferguson's former teams while despite their lavish spending, second-placed Manchester City have also failed to reproduce the level of form they showed last season.

And after watching Tottenham batter United on Sunday and emerge with a draw, Wenger reflected on the fall in standards that he thinks Arsenal could have taken advantage of this season.

"I saw Tottenham v Manchester United and you think (about) the difference between us and Manchester United when you see them play...," Wenger said.

"It was a fantastic opportunity (to win the league) this season. To catch Manchester United now is out of sight at the moment.

"We have to get closer to the people in front of us first before we can think that. Man United is far but there is no untouchable team in the country at the moment.

"It should not be difficult (to get in the top four) but it will be tough."

Key to Wenger's struggles, of course, has been the departure of Robin van Persie, who has repeated his superb form last season with his new employers at Old Trafford.

Inconsistency has also been a major problem, with the highs of putting seven past Reading and then Newcastle outweighed by the low points - home defeats to City, Swansea and Chelsea, not to mention the embarrassing Capital One Cup exit as part of npower League Two side Bradford's shock run to the final.

Theo Walcott, who last week signed a new contract, said there is a lack of self-belief in the Arsenal camp and his manager concurs.

"I agree with him," Wenger said. "The players come out and think 'we could have done better'.

"But when you look at the first half (against Chelsea on Sunday) we lost goals we shouldn't lose, 50/50s you cannot lose in big games.

"Last year we could win big games and on Sunday you come out of the game and think 'what is happening?"'

Wenger hopes to sign two players before the transfer window shuts, with defensive midfield a possible priority given Mikel Arteta and Francis Coquelin are out injured and Abou Diaby has just returned from a long-term thigh injury.

Wenger professed his admiration for West Ham player Mohamed Diame, saying: "He has a great presence in the games. I've seen him in games where he's had a big impact.

"They have many players who can be dangerous, but he can drive the midfield."

PA