Thursday’s Europa League clash had to be put back an hour after thousands of Germans arrived at The Emirates without tickets and forced their way past barricades as they tried to get in.

Others who had bought from touts managed to get into home areas at the stadium and German World Cup winner Mertesacker admitted it was a worrying time as the players waited to see if the game was even going to go ahead.

“I don’t know what happened outside, I just wanted to make sure my family was okay,” said the centre-back.

“Some people said ‘tell them to stay at home’, because there were such big problems here outside of the stadium.

“It was very difficult to handle because we were already in the dressing-room and then we found out very late that we extended the decision about the kick-off for another hour.

“It’s kind of annoying, you want to find out if you actually play or not. That was in doubt as well. But we wanted to play, we wanted desperately to play.

“Eventually everyone made sure that we can continue. But it took us 45 minutes and I think we are quite happy with the way it ended, but it took us a long time to get going here really.”

Arsenal won 3-1 after going behind to an early goal and the comeback will have set up the team for the tough trip to champions Chelsea on Sunday.

“We are confident because we have such a big squad,” added Mertesacker. “Everybody wants to be in the team for Sunday.

“We have to learn quickly from the [4-0] defeat at Liverpool and not do the same mistakes again.

“They beat us really on the break, and I think Chelsea will try to do the same on Sunday. We need to show more discipline."

The Gunners beat the Blues in the FA Cup Final and Community Shield, but Mertesacker added: “We have certainly found our rhythm against Chelsea at Wembley, but there’s different circumstances at Stamford Bridge.

“We really made the difference on those occasions, so it’s really down to us. I think confidence-wise, we should be on top of that.”