Alasdair Hooper looks at the big talking points ahead of another busy weekend of European football.
Football and the Christmas period – a gloriously chaotic period that none of us can take our eyes off.
December is now here and, year after year, we are always reminded just how crucial the winter period is.
A large part of that is the sheer number of games that teams have to play, with some sides already showing signs of cracking.
These are the games you should keep an eye on this weekend as teams battle fatigue as well as their match day opposition.
1. Will Maurizio Sarri turn the tide against the Premier League leaders?
How quickly things can change.
With a defeats to Wolves and Tottenham sandwiching a victory against bottom-of-the-table Fulham, Chelsea suddenly aren’t looking the force they once were under Maurizio Sarri.
The Blues have now slipped to fourth in the league after suffering their shock midweek defeat and life does not get much easier.
This Saturday they play host to the team everyone is cared of playing right now in Manchester City.
Pep Guardiola’s Premier League leaders look capable of turning over anyone, regardless of which players take to the field, and the prospect of facing them is sure to be a daunting one for Chelsea.
As ever, a clash between two of the Premier League’s ‘big six’ is sure to garner attention but with Arsenal lurking behind the Blues – and Liverpool trying to keep pace with City – it’s a match neither side can afford to lose.
It will make for enticing viewing.
2. Will La Liga’s surprise package keep on upsetting the odds?
This weekly piece probably hasn’t touched on this team enough as it should have but it’s time to change that – Alaves have been the story of the La Liga season so far.
Now in their third season since their most recent promotion to La Liga, the side from Vitoria-Gasteiz sit fourth in the table, above the likes of Real Madrid.
They have already claimed some notable scalps this year – beating Real Madrid in October stands out particularly – and this weekend they come up against the team that sit a point and a place ahead of them in Atletico Madrid.
Alaves’ team include a few familiar names – Stoke City and Manchester City fans might remember John Guidetti while West Ham fans would do well to conjure up images of the forgettable Jonathan Calleri – but something about this team is working well right now.
While they have stuttered lately with a draw and a loss in their last two league fixtures, there seems plenty about this side that suggests they will give Atletico Madrid a tough time.
3. Will Barcelona remain on top in their city derby?
Everyone loves a derby fixture and in Spain we get to see top of the table Barcelona face their city rivals Espanyol.
This has been a rather one-sided rivalry of late but Barcelona are not the invincible force they once were, even though they are currently top of the pile.
Two defeats and four draws, in the league this season for Ernesto Valverde’s side, show there are vulnerabilities there and Espanyol, in seventh, are only seven points behind.
However, what is going against Rubi’s side at this moment in time is there run of form – three losses on the bounce in the league suggest it could be an uphill battle.
But stranger things have happened in football.
4. Will the Dortmund feel good factor continue with a win over their rivals?
Life is pretty good right now at Borussia Dortmund under Lucien Favre.
While we in the UK are obviously given regular updates on the promising Jadon Sancho, Dortmund are currently flying high at the top of the Bundesliga, seven points clear.
While Bayern Munich continue to have their mini crisis of confidence all eyes are on Die Schwarzgelben to see if they can reclaim their first league title since the days of Jurgen Klopp.
But this Saturday they have a tough task facing Ruhr rivals Schalke in the Revierderby.
Last season’s runners-up Schalke impressed many but are currently languishing in 14th after a slow start this time around under young manager Domenico Tedesco.
But the talent Schalke possess is still unquestioned and there is nothing like a derby to bring the best out in them.
5. Will Manchester City follow up their impressive downing of the Gunners?
Joe Montemurro’s Arsenal have been – quite rightly – gaining all the plaudits for their incredible form in the WSL.
But last weekend served as a bit of a reality check as Manchester City rocked up and dished out the Gunner’s first defeat of the season.
The 2-0 victory for Nick Cushing’s side, courtesy of a Georgia Stanway double, saw Manchester City close the gap on the Gunners to three points.
This Sunday, City – who are now the last unbeaten side in the league – can follow up that impressive result with another big performance as they host third-placed Birmingham.
Victory for City will take them level on points with Arsenal, having played a game more, but suddenly the title race in the WSL looks very much on.
Follow Alasdair on Twitter at @adjhooper1992