The turn of the year is always a pivotal moment in the season.
For the Premier League, the grueling Christmas period always has a telling effect on the eventual outcome. But, how teams across Europe's other major leagues restart their respective campaigns after the winter break is just as important.
It stands to reason that some teams will not be able to maintain the form which took them to their end-of-year positions. This does not mean they cannot recover, but merely that they might endure a dip in form before the season run-in.
Here are seven teams who could see their seasons slide in the new year.
Who would have thought just a few weeks ago that Manchester United would be level with Manchester City at the top of the Premier League table on Boxing Day?
City began December five points clear of their local rivals, but defeat at Chelsea and a goalless draw at West Brom have seen them let that advantage slip.
This is not to say that Roberto Mancini's team will suffer a title capitulation in the manner of Newcastle back in the mid-'90s. However, with key midfielder Yaya Toure about to go off to the African Cup of Nations just as his club are suffering their first wobble of the season and games against Liverpool and Tottenham coming up in the league next month, this could be the most testing period of their domestic season.
Lowly Levante stunned the football world earlier this season when they topped La Liga for the first time in their 102-year history.
Las Granotas were only top for one week, but they achieved that via an unbeaten nine-game run at the start of the season that included wins over Real Madrid, Espanyol and Malaga.
The ragtag group of journeyman and veterans maintained their one aim was to avoid relegation, and their subsequent run of five defeats in the their last seven games suggests they were right to keep their sights set so low.
Their early-season exploits mean they are still fourth in the table over the winter break, but it is highly unlikely they will be bothering the Champions League positions come May.
Luis Suarez has proven himself to be both a blessing and a curse for Liverpool since joining them a year ago.
The Uruguayan has established himself as one of the most exciting and lethal forwards in the Premier League, but he has let controversy and misconduct leave his club in a tricky situation.
Suarez is Liverpool's top scorer with five league goals—none of his teammates have more than two—but he is facing an eight-match ban (pending appeal) for his alleged abuse of Patrice Evra on top of the the one-match suspension he will definitely serve for flipping the bird at Fulham fans recently.
With Suarez absent from the Liverpool attack for such a long time, it seems unlikely that the Reds will be able to stop a gap between them and the other clubs with Champions League ambitions pulling away from them over the next quarter of the campaign or so.
Udinese suffered several setbacks at the start of the season; they lost star men Alexis Sanchez and Gokhan Inler to Barcelona and Napoli respectively, and they lost their Champions League playoff to Arsenal.
Despite that, the Zebrette bounced back tremendously well, and they currently sit third in the table just two points off joint-leaders Juventus and AC Milan.
However, they are now far too over-reliant on star striker and captain Antonio di Natale. The 34-year-old has scored half of his team's 20 league goals so far this season.
For them to repeat their feat from last season of reaching the Champions League playoffs, they will have to finish one place higher than last term due to Italy's drop in the UEFA coefficients. With Lazio and the resurgent pair of Inter Milan and Roma breathing down their necks, they will need more than just di Natale's goal in the second half of the season to maintain their current position.
The Canaries have already made magnificent strides under Paul Lambert to get where they are now.
Two successive promotions have seen them return to the top flight, and they go into the new year sitting comfortably in mid-table.
However, alarm bells are ringing after their 2-0 defeat at home to Tottenham meant they have still not kept a clean sheet in the league so far.
Unless they can learn how to shut out opponents, they may find themselves slipping towards the relegation zone soon. Survival is well within their grasp, but it could be enough to give them an end-of-season fright.
Los Rojillos are another side who can be pleased with their work at the mid-point of the Spanish season.
Despite being drubbed 8-0 at Barcelona and 7-1 at Real Madrid, Osasuna have only lost three matches so far and sit fifth in the table.
However, with the likes of Sevilla, Malaga, Athletic Bilbao and Atletico Madrid not far behind them, manager Jose Luis Mendilibar will have a task fending off those more illustrious clubs when the season resumes on Jan. 7.
Villa have spent most of the first half of the season in the top half of the table, but a run of just one win in their last seven games has seen them slide down to 12th.
The absence of striker Darren Bent has been particularly felt recently, with the team earning just one point and scoring as many goals in their last three games.
Manager Alex McLeish's pragmatic style has not ingratiated itself with the club's fans, and other teams have quickly learnt to cope with their one-dimensional style. If rumours of rifts with certain key squad members are to be believed, then that is just another reason for the atmosphere around Villa Park to be pessimistic.