Wojciech Szczesny believes Laurent Koscielny’s return from injury will make a huge difference to Arsenal’s efforts to climb the Premier League table.

Koscielny featured in the Gunners’ back line on Sunday for the first time in almost a month as they withstood sustained pressure to triumph 2-1 at West Ham and leapfrog their opponents into fifth place.

An ongoing Achilles problem over the past three months meant the Upton Park clash was only the Frenchman’s third appearance during that time – but the resumption of his partnership with Per Mertesacker is crucial for the second half of the season, according to Szczesny.

“He [Koscielny] is as good as you’re going to get in England, I think,” said the Arsenal goalkeeper.

“When he’s fit and he plays with Per they make a great couple of centre-backs. They’ve played together for quite a while and they know each other’s games.

“So having him back is massive for us and I hope that can continue and he can avoid injuries. It’s obviously much easier when you’ve got players back.

“The two centre-backs headed away so many balls and made so many blocks, they deserve so much credit. I’m very happy for them because they do get some unfair criticism sometimes.

“We had to dig very deep against a very good side – it was by far the strongest West Ham side I’ve ever played against. It was quite ugly at the end but we got through.

“We could have made it easier for ourselves by scoring another goal on one of the counter-attacks but it didn’t happen for us, so we just had to defend and put bodies on the line and thankfully we did that.”

Former Arsenal midfielder Alex Song had an early goal controversially ruled out for offside at Upton Park before the visitors seized control with two goals in the space of three minutes just before half-time.

Santi Cazorla netted a penalty after he was adjudged to have been brought down by James Tomkins and Danny Welbeck turned home Alex Oxlade-Chamberlain’s cross to double the Gunners’ lead.

Cheikhou Kouyate headed one back for the Hammers after the break but, although the home side dominated possession, Arsenal held on to record their second successive 2-1 victory.

And the Gunners will climb into the top four on New Year’s Day if they can claim another win at Southampton, the side now directly above them in the table.

The Saints have recovered from a recent blip by taking seven points from their last three games, with victories over Everton and Crystal Palace and a draw against leaders Chelsea.

“We said before the Christmas games that we wanted nine points. We’ve got six out of six so far and we’re in a good way to get nine,” added Szczesny.

“I know Southampton got a fantastic result against Chelsea so they won’t be short on confidence. But we’ll look forward to it and hopefully we can get another three points.

“The position we’re in, we have to look at short-term goals and the short-term goal is to get three points against Southampton. Whether we can catch other teams in front of us, we’ll find out.

“Of course we want to catch up with Chelsea and Manchester City, but for now we have to come up the table and see if we can put pressure on them.”