After back-to-back defeats from winning positions, the Gunners boss insists his team must gain focus and calls for it to take the opportunity to react against Manchester United.
"It is a massive opportunity [next Sunday] because you feel we have given six points away in the last two games in a way that is unbelievable. It is time for us to wake up and be focused - we have a good opportunity to do that against Manchester United," he told the club's website.
Wenger’s side slipped to a 3-2 defeat against Swansea City at the Liberty Stadium on Sunday - the Gunners second consecutive defeat in the Premier League after also losing out to Fulham two weeks ago.
"That's now twice - at Swansea and at Fulham - where we have given the game away," Wenger told the site.
"It is down to a lack of composure and the right decision-making. It is alarming because at Fulham we were 1-0 up and we lost the game. Today we came back to 2-2 and straight away we gave the third goal away. It is really a concern.