Defeat by Celta Vigo at Camp Nou on Sunday condemned Barcelona to a seventh loss of the season - their most since 2007-08 - meaning they can finish third at best in La Liga.
Having won eight of the past 12 league titles coming into this campaign, where has it gone so wrong for Barca?
IF NOT MESSI, THEN WHO?
Lionel Messi has 30 Liga goals to his name, and coach Ronald Koeman said after the Celta defeat: "If he's not at the club, who is going to score the goals for us?".
Barca's second-highest scorer in the league is Antoine Griezmann, with 12 goals, five of which have come in the last ten games.
Barca allowed Luis Suarez to join Atletico Madrid last summer for a nominal sum, and the Uruguayan's 20 goals have shot them to the brink of the title.
Messi's contract expires next month. Should Barca fail to retain him, they could find themselves in a battle for Champions League next term, rather than a push for the title.
Koeman has often lamented the fact that sides have been clinical against Barca, but that reflects the quality of the chances his side offer up.
They are still as reliant as ever on 34-year-old Gerard Pique and neither Clement Lenglet nor Samuel Umtiti have looked capable of partnering him.
However, the habit of relying on Pique was ruthlessly exposed by Paris Saint-Germain in the Champions League.
The image of Kylian Mbappe sprinting away from Pique in their 4-1 Camp Nou win has turned into an internet meme.
A reliable partner for, and successor to, the centre-back are required.
ANOTHER WRONG APPOINTMENT
Barca's decision to sack Ernesto Valverde, who had won back-to-back titles, while top of the league in January 2020 has never seemed as miscalculated.
His replacement, Quique Setien, was fired that summer and replaced by Koeman.
While a club legend as a player, Koeman's coaching record at club level made him a gamble that seems to have backfired.
Barca won the Copa del Rey - the Dutchman's first trophy since 2009 - however their big game record has suffered.
Local media reports suggest he is on the brink of exiting, with another club legend, Xavi Hernandez, in the frame to replace him.