LONDON • Returning to London after Champions League elimination at Barcelona's hands, Arsenal manager Arsene Wenger faces more uncomfortable questions than ever before about his stewardship of the English football club.

A season that was still full of hope at the turn of the year is now unravelling in all-too-familiar fashion, with Arsenal out of Europe, out of both Cup competitions and trailing Premier League leaders Leicester by 11 points, albeit with a game in hand.

They remain on course for a top-four finish, but Champions League qualification is losing its consolatory effect on the club's fans, many of whom have come to see it as a sign of the culture of mid-level achievement that Wenger has allowed to take root at the Emirates Stadium.

"I think the natives have turned. There's more people who want the boss out than want him in," former Arsenal striker Ian Wright said on BT Sport after Arsenal's 1-3 loss to Barcelona on Wednesday, which completed a 5-1 aggregate defeat.

With Chelsea floundering, Manchester City fatally inconsistent and both Liverpool and Manchester United in transition, this season had held the promise of a first league title for Arsenal since 2004.

Instead they have failed to grasp the nettle, with outsiders Leicester and - worse - arch-rivals Tottenham Hotspur surging past them to fight out the most improbable English title duel in recent memory.

"This was the perfect year for Arsenal to win the Premier League and they've missed it," said Emmanuel Petit, another former Wenger protege.

FA Cup wins in 2014 and 2015 ended Arsenal's eight-season silverware drought and indicated that the club were re-acquiring the trophy-winning know-how that characterised the first nine seasons of Wenger's tenure, which yielded three Premier League titles and four FA Cups.

The signings of Mesut Oezil and Alexis Sanchez also hinted at a new dawn, but Arsenal remain bedevilled by the same frailties: recurrent injuries, exacerbated by unaddressed weaknesses in key areas of the squad, tactical naivety and, crucially, a bewildering lack of backbone.

On Wednesday, they gave European champions Barcelona a scare with a spirited display. However, the difference in quality in front of goal was the deciding factor as the Catalan side's South American trio - Lionel Messi, Luis Suarez and Neymar - all netted to take their combined tally for the season to 106.

"We have to admire art and they have two or three players that transform normal life into art," said Wenger. "I have to say we played against a team with the best strikers I've seen. The three are exceptional and from nothing they can create a chance."

By contrast, Arsenal's whole squad have managed just 72 goals this season and their downfall was once again a lack of cutting edge up front.

"They are not getting results you might think, for the signings they make. It's something to analyse," said Barcelona manager Luis Enrique, referring to the fact only Manchester City of the Premier League sides were left in the last eight.

The achievements of Wenger's 20-year tenure - notably the successful move to the Emirates and the establishment of Arsenal as a global brand - have earned the 66-year-old Frenchman iconic status at the club.

Fan discontent is becoming increasingly difficult to ignore, however, and reports this week suggested that it could prompt Wenger to walk away from his post before his contract expires next year.

Celebrity fan Piers Morgan, the newspaper editor turned chat- show host, continues to fire up the #WengerOUT campaign on social media, while a banner held aloft during the recent FA Cup win at Hull read: "Arsene, thanks for the memories, but it's time to say goodbye."

Arsenal are on course to qualify for the Champions League for the 20th season running, but, after six successive last-16 exits they have become the competition's perennial wallflowers - always at the party, but never on the dance floor.

More damning still, they are now a byword for tolerated under-achievement.

AGENCE FRANCE-PRESSE, REUTERS