Barcelona’s Lionel Messi fights for the ball against Athletic Bilbao’s Mikel Balenziaga during their Spanish Super Cup second leg match at Camp Nou stadium in Barcelona on Monday. (Reuters)

DPA/Madrid

Just 10 days ago, Barcelona seemed to be well set up for another successful season.
They had signed no new players - they are banned from doing so by FIFA for having underage foreigners in their youth scheme - but several promising youngsters had been promoted from the B team, and defender Thomas Vermaelen was finally fit.
Even more importantly, Lionel Messi and Neymar had returned from the Copa America unscathed, while Luis Suarez - the third element in Barca’s South American attacking trio - had not even gone to the tournament, due to a FIFA ban.
All seemed to be set fair for another prosperous campaign for the Spanish and European champions. However, Neymar then went down with mumps and left-back Jordi Alba was sidelined with a pulled muscle.
The makeshift Barca defence was ripped to shreds by Sevilla in last week’s European Super Cup, though the Catalans just managed to hold out for a tight 5-4 win. Worse was to come three nights later, when Barca astonishingly crashed 4-0 at Athletic Bilbao in the Spanish Super Cup first leg.  Their problems were confirmed by Monday’s 1-1 draw at home to Bilbao.
In their first three official matches of the season, Barca have looked brittle in defence - conceding nine goals - ponderous in midfield without veteran playmaker Xavi, and imprecise in attack, with Messi only shining at free-kicks.
In addition, key defender Gerard Pique will be suspended for three or four games after being sent off for dissent Monday.
“Bilbao and Sevilla have shown the whole of Spain that Barca are far from invincible,” commented Radio Marca.
“They are conceding goals easily and are struggling to score them.”
The big question now is whether anyone can take advantage of Barca’s sudden vulnerability.
The obvious suspects, of course, are Real Madrid. However, for the first time in many years, Los Merengues have made no major pre-season signings - though they are poised to take Mateo Kovacic from Inter Milan.
Iker Casillas’ departure for Porto was noisy and acrimonious, but president Florentino Perez has at least persuaded Sergio Ramos to stay put - albeit at the price of a substantially increased salary.
Real are undecided whether to sign goalkeeper David de Gea from Manchester United, or instead try to get by with Keylor Navas and Kiko Casilla.
Cristiano Ronaldo is also rumoured to be less than enamoured with the meticulous methods of new coach Rafa Benitez, and Karim Benzema is reportedly considering a move to Arsenal.
“There are many question marks hanging over the Real Madrid of Benitez,” commented radio station Cadena SER.
“Who will be the goalkeeper? Is (Luka) Modric fully fit? Will Ronaldo get on well with Benitez? Will (Gareth) Bale finally fulfill his potential?”
For the first time in more than 40 years, the close season’s highest spenders have been Atletico Madrid, who have livened up their attack with Jackson Martinez, Luciano Vietto and Yannick Carrasco.
Just as importantly in defence, Diego Simeone has managed to bring back Filipe Luis from Chelsea and hang on to Diego Godin, though Joao Miranda has left for Inter.
Simeone has promised a more entertaining and aesthetic Atletico, and that could be bad news for Barca and Real.
Are there any other teams capable of threatening the big three?
Cash-strapped Valencia have made few signings and could lose key defender Nicolas Otamendi as the transfer window ticks down.
Sevilla, in contrast, have made their usual clever purchases - Michael Krohn-Dehli and Ciro Immobile among them - but have lost their leading scorer Carlos Bacca to AC Milan.
Finally, a good outside bet for success could be Villarreal, whose attack will be led by veteran Roberto Soldado and promising youngster Leo Baptistao.