Laurent Koscielny reckons Gunners' new-look defence has injected renewed confidence into Arsene Wenger's men

London: Laurent Koscielny believes Arsenal`s defensive rethink can help drive Arsene Wenger`s side to a top-four finish in the Premier League.

The Gunners will face reigning champions Leicester City at the Emirates Stadium on Wednesday buoyed by their FA Cup semi-final success against Manchester City that set up a Wembley final with Chelsea.

Sunday`s last-four victory followed Arsenal`s win the previous week at Middlesbrough when the under fire Wenger responded to his side`s alarming dip in form by changing to a three-man backline.

Now, having registered back to back victories with his new line-up, Wenger is likely to stick with the formation for the visit of Craig Shakespeare`s revived Leicester side.

A third successive win will move Arsenal to within four points of fourth-placed City, currently in possession of the final Champions League place on offer to Premier League clubs, and three points behind Manchester United in fifth, 24 hours before the Manchester derby.

Koscielny, the Arsenal centre-back, had no doubt that Wenger`s decision to change things around has helped increase the chances of the club ending a difficult season on a high.

"There was a tactical turnaround, but we`ve been working on it for 15 days," the France international said.

"In that system, there are players who are good. It`s good for the collective.

"I think we also found confidence in this system with three defenders. We are more solid behind."

Intense speculation surrounds the future of Wenger, with the 67-year-old Frenchman yet to reveal if he will sign a new Arsenal contract when his current deal expires at the end of the season.That debate looks set to continue, but Wenger will be increasingly confident he can re-frame the discussion by maintaining his record of never having missed out on a place in the Champions League in a full season with Arsenal since he took charge over 20 years ago.

Koscielny added: "Before this (Manchester City) game, we were in a fairly dark period. We have lost confidence. This victory allows us to regain confidence, and serenity, even if everything has not been perfect.

"The future of Wenger, I don`t know if it weighs on recent results. We`ll never know. But, we are professionals. Each week we go to the pitch to give the best of yourself and win the most matches.

"The bad results are also due to us."

Leicester enter the game in London potentially just one victory away from safety after five wins from seven games under manager Shakespeare took them to 37 points.

But Shakespeare, who took charge after the Foxes` Thai owners sacked title-winning manager Claudio Ranieri following an alarming dip in form that left the Midlands club on the brink of the relegation zone earlier this season, was not taking anything for granted against an Arsenal side whose inconsistent league form has angered many of their own supporters.

"Seeing the Arsenal match (against Manchester City) it didn`t look like turmoil to me, there were players fighting and they thoroughly deserved to win in the end, even though it was a close game," Shakespeare said.

"I`m not sure how many points it will take (to stay up) and the weekend proved that... We have to make sure we look after our own club. You are not sure what`s around the corner."

Leicester captain Wes Morgan (hamstring) and striker Islam Slimani (groin) have both been ruled out of the Arsenal match.

"Unfortunately, Wes won`t make it," said Shakespeare. "He has just overstretched his hamstring. It hasn`t gone into a full blown pull, but we have to be mindful.

"So as a precaution he is out and then we will look towards Saturday at West Brom."