Arsenal's Arsene Wenger: Back-three formation is 'an option' vs. Man City

Arsene Wenger has not ruled out using a back-three formation in Sunday's FA Cup semifinal against Manchester City, although he refused to give anything away about his tactical plans.

Wenger switched to three at the back for the first time in 20 years for Monday's 2-1 win at Middlesbrough to stop Arsenal's defence from leaking goals after four straight Premier League away defeats.

The 67-year-old could repeat the experiment at Wembley this weekend, although he remains without injured centre-back Shkodran Mustafi for the key clash.

"It's an option, yes. But what will I do? You will understand, I won't tell you now," Wenger told a news conference on Thursday.

It is no surprise that Wenger is keeping things close to his chest as City manager Pep Guardiola now has to prepare for two different tactical possibilities against an Arsenal side that is often criticised for being too predictable.

But Wenger said that was not the reason for his sudden tactical switch.

"It was more designed to give us a bit more defensive solidity because recently away from home we conceded too many goals," Wenger said.

Mustafi's absence with a thigh problem could convince Wenger to return to his normal back four, although 21-year-old Rob Holding performed well against Middlesbrough in his first Premier League start since August.

Danny Welbeck is also doubtful for the game after missing the Middlesbrough clash, while goalkeeper David Ospina and forward Lucas Perez are both still sidelined.

For Arsenal, Sunday's game represents perhaps the last opportunity to salvage a disappointing season, with the club struggling to secure Champions League qualification.

A win would certainly help turn the fan mood around and ease some of the pressure on the under-pressure manager.

But Wenger, who has yet to divulge whether he plans to stay in charge after this season, insisted that his own future will not be determined by the team's potential FA Cup success.

"It doesn't play any part in that," he said. "The FA Cup is a very important game for me because it's the next game and because it's an opportunity to win a trophy this season. So of course we are all fully focused on that. My future is Sunday."