Fresh from receiving a gong for his outstanding contribution to a London Club at a major charity event last night, and in the wake of Wednesday’s 2-1 win over QPR, it was a return to form for Arsenal boss Arsene Wenger at today’s (Friday) press conference.

Looking relaxed and joking again with sports reporters at his weekly press conference at the Gunners’ training grounds in London Colney, Wenger said: “Every day you have to criticise somebody or you don’t sleep well overnight. And because we are in a public job, we have to accept that.”

He was speaking to reporters hours after receiving an accolade at last night’s London Football Awards in aid of Willow Foundation, which rewards the unsung heroes of London football.

At that event, Wenger told the audience: “I’ve been very lucky in my life to work for such a great club. Football is something special.”

Willow Foundation organises special days for seriously ill young adults, and has received thousands in pounds in donations from kind-hearted people in St Albans.

In London Colney this morning, ahead of Monday’s match against Manchester United, Wenger confirmed that Gabriel Paulista is suffering a slight hamstring injury and will be out for two to three weeks.

Thus he will not be available for Monday’s game, “and certainly not against West Ham or Monaco”, said Wenger.

Three days ahead of the FA Cup clash against Manchester United, Wenger said Nacho Monreal might come back – he will have a test run today, and “everybody else should be available, the same squad that played against Queens Park Rangers.

“I believe it will be a very interesting game.”

When asked about forward Danny Welbeck’s “difficulty” in getting in the side, Wenger replied: “Welbeck has played many, many games since he started with the team, and his position is one of three up front, centre-wide or left-wide, he can play anywhere.”

But in response to a question on whether Welbeck’s Arsenal stint ‘is starting to reflect his Manchester United career’, Wenger said: “If you look at the statistics, you will see that is a wrong statement.

“Not every single player can play every single game.”

Reminded that it has been nearly 10 years since Arsenal has won at Old Trafford, he said: “I don’t believe too much in history. Just in the performance of the day. At the moment we are doing very well away from home. The size of the pitch is exactly the same everywhere.

“It is down to how much effort we put in to winning the game.”

Arsenal “wants to keep the FA Cup,” Wenger added.

In relation to controversy over the now infamous spitting incident, where both Newcastle United’s Papiss Cisse and Manchester United’s Jonny Evans were charged with spitting by the FA, Wenger said: “I think it is not acceptable.

“We play against Man. United on Monday night, so I don’t have too much to [say] about that. It is up to the FA to deal with it.”

The room erupted into laughter when quizzed about changes in managers’ behaviour towards each other in the technical area, as Wenger asked: “why do you look at me?”

He said: “Ideally you want us all to behave in a perfect way, maybe to build a wall between the two dug-outs, the bigger the distance the better it is.

“In a modern stadium it is much better if there are zero instances, because we are far apart from each other. When the dug-outs are very close everyone speaks to an official and then it becomes very controversial.

“And the incidents can explode very [quickly]. The distance between the two dug-outs is a very important part of peace.”

• Manchester United V Arsenal, Old Trafford, Monday March 9, 7.45pm