Arsene Wenger believes Arsenal’s impressive form throughout 2015 is down to his side’s increased defensive strength since their last visit to Southampton.

The Gunners return to St Mary’s on Boxing Day for the first time since their shambolic 2-0 defeat to Southampton on the first day of the calendar year.

As well as conceding two untidy goals on that occasion, goalkeeper Wojciech Szczesny was disciplined and dropped from the side following a well-publicised smoking incident.

But Wenger’s side then embarked on an excellent run of form, losing just three times in all competitions for the remainder of last season – and that has spilled into the current campaign as well.

Arsenal have garnered more Premier League points than any other club since that New Year’s Day debacle on the south coast and sit second in the table, just two points behind Leicester.

“I will never forget that game because there was also a lot around the game afterwards,” said the Gunners boss. “It was a turning point for us in 2015.

“I think what changed is that we are more stable defensively – we are certainly more resilient and, if you look at our record, we are more consistent with our results.

“But we have to be realistic in our job – we still have to go to Manchester United, Manchester City, Tottenham and Liverpool.

“There’s a long way to go, there are 21 games to play and we have to be pragmatic and earn the right to win in every single game.”

Wenger leads his side into the holiday programme – which also includes home games against Bournemouth and Newcastle – with an unchanged squad.

Alexis Sanchez suffered a setback in his recovery from a hamstring injury earlier this week and will remain out of action until at least the second week in January.

Club captain Mikel Arteta had been pencilled in to play some part in the Gunners’ festive fixtures, but Wenger now plans to give the midfielder a run-out for the Under-21 side early in the new year instead.

Arteta, who has not featured in the first team since their 2-1 defeat at West Brom a month ago, is still battling to shake off the calf problem that also plagued him last season.

“At the moment he is close, but every time I put him in there is a setback,” added Wenger.

“This time I want to be a bit more cautious and maybe get him to play one or two games for the reserves before he comes back.”