Over the course of a mere month, FC Barcelona's season has been turned on its head.
Cruising, undefeated in La Liga until January and favourites for a fourth Champions League title in just eight years, the Catalans looked invincible.
However, in their past 13 games, the Blaugrana have managed a measly six wins.
It is a run of form not seen since the pre-Guardiola era, and if the media are to be believed, it can only spell disaster.
Problems, however, always have solutions, but first they must be highlighted for all to see.
So what is really going wrong at the Camp Nou?
Xavi, the heartbeat of Barca's game.
Barca play a game which fundamentally focuses on keeping the ball to hone technical ability, but do not underestimate the amount of hard work the players put in to fulfill their roles.
In possession, off-ball movement is key to creating space and opening passing lanes.
Off the ball, organised and intense pressing wins back possession and the impetus of play.
One of the most frustrating sights in recent weeks has been the number of times players have been spotted simply walking about the pitch.
Clearly the players are both mentally and physically fatigued, many coming off a busy summer at Euro 2012.
Much of the problem is owed to an approach to fitness training known as "periodisation."
Barcelona use a distinctive conditioning program which aims for the players to reach peak fitness towards the end of the season. The trade-off, however, is that form and fitness dips in Europe's winter months.
Indeed, Goal.com's Paul McDonald has pointed out that throughout the Guardiola years, February has proved troublesome.
Perhaps finally, Barca will pay more severe consequences for this fitness tactic.
Xavi, Barca's maestro, has particularly struggled for fitness.
The Catalan midfielder has been carrying a hamstring strain and bears the signs of an overworked player.
Without a fit Xavi, Barcelona's game has severely lacked tempo and fluidity, two hallmarks of successful "tiki-taka" football.
While Iniesta and Messi have continually provided the spark this season, one must not underestimate the influence of Barca's No. 6.
Caretaker manager Jordi Roura has done his best.
Messi, Iniesta, Xavi, Pique...Barcelona's roster has been so full of talent that many have claimed any idiot could manage such a team.
All teams, however, need someone at the reigns. One must not forget that the troubled team Pep Guardiola inherited was just as talented.
Tito Vilanova's absence as he undergoes cancer treatment in New York is a tragedy in more ways than one. The footballing significance cannot be underestimated.
The new boss had proven an intelligent, charismatic and adaptable coach during his short tenure.
It is clear that "Tito" was doing much more behind the scenes under Guardiola than he was given credit for.
The unfortunate circumstances have not only interrupted tactical plans, but have also clearly impacted team morale.
Jordi Roura finds himself in an unfortunate situation as caretaker, and under the circumstances, criticism may be harsh, but somebody has to say it: He has not been great.
During a period in which squad rotation should have been key, the interim manager has insisted on a very consistent starting 11, further draining key players of fitness.
He has also failed to make smart tactical changes under pressure, something Vilanova has proven expert at, as evidenced particularly against AC Milan, when Barca looked positively lost for answers.
Barca need their gaffer back.
Fabregas and Iniesta too often drift into the same positions.
Perhaps Barca's most poignant tactical problem in recent weeks has been the lack of width in attack.
B/R tactical analyst Sam Tighe recently pointed out that players "rarely hit the byline" in the first leg against AC Milan.
Indeed, the problem is that the Blaugrana have not been playing with natural wingers all season. Width has largely been provided by overlapping runs via Jordi Alba, Adriano and Dani Alves.
Pedro Rodriguez has withdrawn into pockets of space on the right midfield and Iniesta has normally occupied the left, naturally gravitating infield.
While overlapping width is useful, against more stubborn, compact defences, it is imperative that the defensive line is stretched horizontally by players hugging the sidelines in advanced areas.
When it seemed so obvious that the Catalans needed width against AC Milan, Roura failed to make the necessary changes.
Real Madrid proved too good for Barca.
For the most part, Barca have impressed effortlessly this season, but have they been seriously tested?
Prior to the recent bout of Clasicos, Barcelona had already taken on Real Madrid three times this season, losing the Super Copa on goal difference and conceding a draw in a league fixture at the Camp Nou.
The other only real test was provided by Celtic in the Champions League, where a late goal at the Camp Nou sealed victory for a pretty tame Barca outfit, which then went on to lose in Glasgow.
For a team at the top of the league table, the Blaugrana defence has been horribly poor all season.
Jordi Alba's defensive weaknesses have been exposed by most above-average sides, while the need for more quality in central defence remains a massive problem.
Vilanova's men have too often been bailed out through extraordinary attacking feats, and now that their attack is similarly being tested, the defence has not pulled its weight.
AC Milan and Real Madrid
Essentially, the cracks have always been there; it has simply taken a very good team to come along and brutally expose them.
Milan and Madrid were both able to blight the narrow Barcelona attack while hitting them effectively on the counter.
If Barca are to make a miraculous comeback and march towards the Champions League final, they will need to improve more than their fitness.
What do you think have been Barca's biggest problems? How do they explain the slip in form? What are the solutions?
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