When Arsenal and Chelsea went head to head at the Emirates Stadium on Boxing Day, it was Mikel Arteta, not Frank Lampard, who found his position under the most scrutiny.
A month on, however, and while Chelsea's spiralling form has done for Lampard, Arsenal are looking up again under Arteta. The Gunners were without a win in seven games before Christmas but they face Manchester United on Saturday having not lost since.
The turnaround continued at St Mary's Stadium on Tuesday, the 3-1 victory over Southampton meaning Arsenal have taken more points from the last six Premier League games than they did from the previous 14. They have climbed from 15th to ninth in the table. Suddenly the European places are within reach again.
Arsenal's fixture list is about to get a lot tougher. The visit of Manchester United on Saturday is followed by away games against Wolves and Aston Villa and there is a meeting with Manchester City to come after that. But there is growing optimism that Arteta's vision for Arsenal might finally be coming together.
Young stars raise intensity
Arteta spoke about bringing "intensity" and "aggression" to Arsenal's play at the start of his tenure and while there were examples in certain games, most notably against big-six rivals, it is only now that they are producing it on a consistent basis.
It owes a lot to the recent changes in personnel.
Emile Smith Rowe and Gabriel Martinelli have joined Bukayo Saka in the first-team fold and the new emphasis on youth has helped to transform the side's approach out of possession.
Arsenal, sluggish and passive off the ball earlier in the season, are now playing at a far higher tempo, the energy of their precocious youngsters rubbing off on the senior players around them.
Their ferocious, high-pressing performance against Southampton on Tuesday night was arguably their most effective yet.
Arsenal were overwhelmed by Ralph Hasenhuttl's men when Arteta rotated his side for Saturday's FA Cup tie but three days later roles were reversed. "Everyone was running and pressing," said Hector Bellerin. "There was no way out for them," he added.
It was apparent from as early as the first minute, when Granit Xhaka intercepted a Jan Bednarek pass inside Southampton's half and sent Alexandre Lacazette through on goal.
The striker failed to capitalise on that occasion but Nicolas Pepe's equaliser came in similar circumstances and there were plenty more examples over the course of the 90 minutes.
Arsenal's pressing was perfectly executed on the south coast but their physical output has been noticeably higher throughout the recent unbeaten run, the statistics underlining the extent to which their approach has changed.
According to Premier League tracking data, Arsenal are covering more ground and registering more high-intensity sprints than they were before Christmas. They are also making more ball recoveries and winning more duels and tackles.
The increased emphasis on pressing high up the pitch can be seen in their numbers for high turnovers, which have nearly doubled, and pressed sequences, which are defined as opposition passing sequences of three or fewer passes ending end in their own half.
Arsenal are allowing their opponents far less time on the ball to build attacks, in other words, with further encouragement to be found in what's known as PPDA - passes allowed per defensive action. Their average in that metric has dropped from 14.4 to 12.7.
Arsenal are not yet where Arteta wants them to be - "there are a lot of things we have to improve," he said this week - but their youthful energy certainly seems to be taking them in the direction. "I think he's found the way forward," noted Sky Sports pundit Gary Neville earlier this month.
Smith Rowe's instant impact
Smith Rowe, in particular, has been integral to Arsenal's improvement in possession as well as out of it.
The 20-year-old hadn't played a single minute in the Premier League this season before the Boxing Day meeting with Chelsea but he has started every game since and even the newly-arrived Martin Odegaard may now find it hard to dislodge him from the team.
Smith Rowe's creativity has prompted comparisons with Kevin De Bruyne so it's fitting that the Manchester City star is the only player in the Premier League who can match his total of three assists since Christmas.
But it's not just the quality of Smith Rowe's final ball that has made a difference to Arsenal. Rather, it is the little things; the selfless runs to create spaces for his team-mates; the quick one-twos to break defensive lines and send Arsenal away on the attack.
Smith Rowe, an Arsenal player since the age of nine, has brought speed and spontaneity to their previously laboured approach play. His understanding with Bukayo Saka has helped his former academy team-mate flourish on the right flank and his overall impact has won him admirers outside the club as well as within it.
"I really like him," said Sky Sports pundit Jamie Carragher on Monday Night Football after the 3-0 win over Newcastle.
"Those little lay-offs and movements sometimes don't look like the most spectacular things but I tell you what, the players playing with him will appreciate them.
"Sometimes young players want to show everyone how good they are. They get in there and they want to take their chance but at times they take too long on the ball or make the wrong decisions because they are trying to look for the killer pass.
"When you're receiving the ball, there's nothing worse than waiting for it while someone takes two or three touches and players are getting closer to you. Smith Rowe looks like someone who plays the right pass for the team. That's what really impresses me."
Arteta will be wary of leaning to heavily on Smith Rowe given his age and relative inexperience. It is partly for that reason that Odegaard has been brought in on loan from Real Madrid. But there seems little doubt that he has a big role to play in Arsenal's future.
Partey's quality and composure
Thomas Partey endured a frustrating start to his Arsenal career following his £45m arrival from Atletico Madrid on the final day of the transfer window.
The 27-year-old was forced off with a thigh problem midway though only his third Premier League start, against Aston Villa in November, and he aggravated the injury when he was rushed back for Arsenal's north London derby defeat to Tottenham a month later.
He had to wait until mid-January to return for a third time but his performances in the wins over Newcastle and Southampton show why he was regarded as such an important signing by Arsenal's decision-makers.
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There was one moment in particular against Southampton, when he picked up possession on the edge of his own box early in the second half and shimmied away from Yan Valery, creating the space he needed to release Smith Rowe on the counter-attack, which summed up what he brings to the side.
"On Saturday, we had some difficulties against the high press that we resolved today," said Arteta afterwards. "We were much more efficient in breaking their pressing and that's why we were in much better positions. That was a big improvement."
The improvement was almost entirely down to Partey, who has brought skill and composure to the base of midfield.
His ability in tight spaces is invaluable when launching attacks from deep - Partey averages more dribbles per 90 minutes than any other Arsenal player - and he also possesses the vision, intelligence and technical ability to choose and execute the right passes. Like Smith Rowe, he aims to move the ball forward quickly and incisively.
Those who worked closely with Partey in Spain described him as an "all-rounder" who "does everything well" in conversation with Sky Sports in October and Arteta sees intangible qualities in him too.
"I think he's got a different presence - he brings something different to the team," said the Arsenal manager earlier this month.
"It's not just about his talent, it's not just about his physicality, it's who he is as a person. He makes players around him better and that's a big, big quality."
Differences in defence
Arsenal have of course improved defensively as well as offensively.
Between the 1-0 win over Brighton at the end of December and the 3-0 victory over Newcastle earlier this month, they kept five consecutive clean sheets for the first time since 2009.
Tammy Abraham's late consolation for Chelsea on Boxing Day and Stuart Armstrong's opener for Southampton on Tuesday are the only goals Arsenal have conceded in their last six Premier League games.
Only leaders Manchester City have conceded fewer in that timeframe, while only two sides have allowed their opponents fewer shots on target. The expected goals data, both for and against, suggests Arsenal are currently performing better that at any other point of Arteta's tenure.
The defensive improvement is all the more impressive given the changes Arteta has had to make to his backline. Pablo Mari has been sidelined by an injury at centre-back. Kieran Tierney has been absent on a couple of occasions at left-back.
Their replacements, David Luiz and Cedric Soares, have performed well but Arsenal's defensive solidity has more to do with broader structural changes than individual contributions.
The increased emphasis on pressing has forced their opponents further away from goal, for a start, and while Arsenal's average positions show they have pushed higher up the pitch in the last six games, they have also shown impressive resilience and good organisation when forced to defend deeper - as they were at times against Chelsea and Southampton.
It is encouraging for Arteta that his side have been able to keep their opponents at bay in differing scenarios over the last month but Saturday's meeting with Manchester United is a sterner test. Come through it and the sense of progress will grow stronger.
Watch Arsenal vs Manchester United live on Sky Sports Premier League HD from 5pm on Saturday; Kick-off 5.30pm
Pitch to Post Preview - Arsenal v Man Utd build-up, plus: Man City's title charge, Liverpool's return to form, and problems for Tottenham
In this week's Pitch to Post Preview Podcast Sky Sports pundit Jamie Redknapp joins Peter Smith to look ahead to the big Saturday night clash between Arsenal and Manchester United, and gives his verdict on Emile Smith Rowe, Martin Odegaard - and why Man Utd slipped up against Sheffield United.
We also get the inside story on Man City's title pursuit from Sky Sports News reporter Ben Ransom, who explains how one City star has been transformed by Pep Guardiola's methods this season.
And Sky Sports feature writer Adam Bate reflects on Liverpool's much-needed win at Tottenham - and the injuries sustained which could impact both sides. Plus he makes his Pitch for what will happen in the next round of Premier League games…
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