Arsene Wenger has spoken of his shock at Tony Pulis' exit from Crystal Palace and admits he couldn't work without having full control over transfers.

Pulis walked away from Selhurst Park last night over a disagreement with owner Steve Parish regarding the club's transfer policy.

Arsenal face Palace tomorrow and Wenger said: 'We are positive and confident, but we want to start strongly. We want to prepare well. We will just take it game by game.

VIDEO Scroll down to watch Arsene Wenger on Tony Pulis and Arsenal signings

Confident: Arsene Wenger in optimistic mood ahead of Arsenal's opener against Crystal Palace

High spirits: The Frenchman is all smiles as he speaks ahead of the new Premier League season

Shock: Tony Pulish departed Crystal Palace on Thursday night in surprising circumstances

'It was a complete surprise and what consequence that will have I don't know. But he has done a remarkable job, he worked a miracle.

'I was at the managers meeting Monday and he showed no indication of it. I don't know if it will have an impact on the game.

Amid speculation that Pulis' departure surrounded a disagreement over his control of club signings, Wenger added: 'Transfers should be the managers job, if not we are just robots.

'I couldn't work with a Director of Football. The guy's responsible for the results should be responsible for buying the players.'

And ahead of their clash with Crystal Palace in their Premier League opener on Saturday, Wenger discussed his potential team selection.

'Laurent Koscielny should be back and available. The Germans are not ready yet. They could be considered for Everton.

Ready: Laurent Koscielny should be fit to start the new Premier League campaign on Saturday

Impact: Wenger expects Alexis Sanchez to adapt quickly to the Premier League

'There are six or seven teams who are genuine contenders for the Premier League. You only assess the contenders once the window closes.

'I'm happy with the players we've signed. They have integrated well. I could still do something, I won't rule it out. Numbers wise we are maybe a bit short in certain areas, but the depth of the squad is very good. I'm very excited by this group.

'I believe we have a chance because for a long time we were top of the league last year.

'I don't think it will take Sanchez long to adapt, he has all the ingredients to be a very good Premier League player.

'This is certainly the calmest pre-season we've had. But the reality is what happens tomorrow [on Saturday]. But having a serene environment helps.'