London, Feb 24 (IANS): Arsenal manager Arsene Wenger is dismayed by his players' poor tactical awareness after the Champions League defeat to Barcelona at home.

Argentine star Lionel Messi scored late in the second half as Barcelona carved out a 2-0 victory in the pre-quarterfinal first leg match at the Emirates Stadium here on Tuesday evening. Wenger also rued the fact that Arsenal wasted the scoring chances that came their way.

"We were naive. Technically we were very average. We were naive and that's what was frustrating. Similar to Monaco last season. When it looked like we could win this game we gave it away," Wenger told the British media after the match.

"The way we finished our chances is a problem. I felt in the final third we missed something. We were disciplined defensively but we knew that if we had to keep a 0-0 we keep a 0-0." he added. 

"The regret I had was once we looked like we dominated the game, we give the goal away."

The first goal came off a counter-attack after Arsenal had managed to put the visitors' defence under pressure. 

"They are lethal. One thing we couldn’t afford to give them was counter attacks because they are very dangerous. That’s exactly what we did. We pushed too far in their half and got caught. That's down to their quality as well. It’s too easy to blame I think you have to respect the effort the players put in. What is frustrating is that it looked like they might tire," Wenger said. 

"I knew in the last 20 minutes we would have a chance to win the game if we don't make any mistakes and that's the frustration of the night."

Arsenal now face an uphill task in the second leg at the Camp Nou on March 17 and Wenger conceded that Barcelona are favourites to go through to the next stage.

"Barcelona are through 95 percent but we want to go there and play. We have to go there and fight. We will not go there and have absolutely no chance. ," the 66-year-old Frenchman said.

"That (second goal) makes it realistically very difficult, if not impossible. They were better than us. There's no shame to say that. It will be very difficult but we have to try and do our best. It's 95 percent for them and five per cent for us. But you never know."