Wilshere, 20, has spent the entire season on the sidelines after undergoing surgery on his injured ankle last September.

The midfielder has yet to train with the first team and is still confined to training by himself in the gym.

Arsenal have five games remaining this season but Wenger remains cautious over whether Wilshere will play any part.

Wenger said: "I will not take any risks with him. He is making slow progress so we still have to monitor the situation a little bit at the moment.

"We are now in mid-April, the Euros start in the middle of June. Jack has not played for the whole season and anyone who knows what is required at the top level, in terms of intensity, it's getting short now."

When asked if Wilshere's spirits were high, Wenger added: "How can you be at 19 years of age when you're only dream is to play football. He's down.

"Jack is mentally strong. But what is holding him back is that he can't play football, so he can't be happy."

Meanwhile, Wenger wants referees to be allowed to stop the game to consult video technology to make decisions in the Premier League.

Wenger's call comes after a week of high-profile mistakes by match officials which saw two offside goals awarded to Chelsea against Wigan last Saturday and Manchester United deprived of a clear penalty for handball against Wigan on Wednesday.

Wenger said: "Last weekend was a very, very bad weekend. The football authorities on a global scale have to sit together and see how we can improve.

"There are some immediate decisions to make but as well it is time for us to help the referees. To all be united and have a less conservative approach and finally opt for video.

"Video will help the referees. Not question their authority. It will give them more credit, more authority and less mistakes. (We need) instant video replays on the demand of the referee."

Wenger denies it would slow down the game which has been a main concern of FIFA president Sepp Blatter.

He added: "It would not stop the game. It would sometimes give a bigger flow to the game. Why? Because if I am a linesman and an offside decision is a 50-50 I'm tempted to stop the game.

"If I know I have a video behind me I am tempted to let it go if I'm convinced it is a real 50-50 and you could improve the flow of the game and check after."

Arsenal play Wigan on Monday and full-back Kieran Gibbs and midfielder Gervinho could be available after recovering from groin and ankle injuries respectively. Laurent Koscielny is suspended.

Wenger has also challenged former Arsenal defender Sol Campbell to put his money where his mouth is.

Campbell has queried Arsenal's ambition and urged them to sign proven quality if they are to challenge for trophies next season.

"You've got to ask yourself, where are Arsenal going? Do they want to actually win anything?" he told BBC Sport.

"You can have players for the future but it is about getting players who can make a difference now. You've got to push the boat out, swallow your pride and pay a little bit more, put a bit more on the table and get the players in."

Wenger said: "Sol Campbell has a lot of money. His gifts are welcome. If he gives us money we will spend it. The best way to give advice is to show an example."