After a similar loss to Real Valladolid just a few weeks ago, it beggars belief that there would have been another performance during this season that was lacking so much intensity and desire.
The final nail in Tata Martino's coffin was surely hammered in at the Mestalla, Real Madrid the victors in a Copa Del Rey final in which they completely outplayed their opponents.
At least the pressure eased slightly last weekend with a scrappy win over Athletic Bilbao. Four losses in a row would've been an unmitigated disaster in Catalonia.
The Yellow Submarine never make it an easy trip for visiting teams, but it's been six years since they have turned over the Blaugrana, according to FussballWettpoint.
Given Barca's patchy form, there might not be a better time for Villarreal to end their drought; however, a loss last time out to Malaga has curtailed their own charge for a European place.
Currently in seventh position, a win for the hosts to either leapfrog Real Sociedad or keep in touch with them is a must. The last game of the season between the two could then end up becoming a winner-take-all scenario.
But only if the hosts can begin by a win here. With Barca so decimated by injuries, who would bet against them?
Jose Manuel Pinto has to continue in goal despite some reservations about his performances.
An alleged acknowledgement that he won't be at Barcelona beyond this season, via Tom Conn of Inside Spanish Football, plus FIFA's transfer ban leaves Barca with the possibility of third choice Oier Olazabal becoming their first choice next season.
Defensively, the Blaugrana will hope to have Gerard Pique back to partner Javier Mascherano in the centre, even though Marc Bartra deserves to keep his place on current form.
Jordi Alba is still out so Adriano Correia will deputise again, with Dani Alves completing the back four.
If Cani and especially Bruno can escape the shackles of the returning Sergio Busquets in midfield, then Barca's back line will be in trouble all game long.
With nothing to lose now, but everything to gain if there is an unlikely slip-up from either Madrid club, Martino has to play all of his best available players, so Xavi Hernandez and Andres Iniesta will assist Busquets in a familiar-looking midfield.
Alexis Sanchez was lucky to take his place in the starting XI against the Basques, given his petulance in storming straight down the tunnel and not collecting his losers medal in the Copa final.
But his performance, along with that of Pedro Rodriguez, will see both keep their place in a front three that includes Lionel Messi.
Despite not being at his absolute best recently, Messi will occupy the central areas and should have more than enough to keep Barca transfer target Mateo Musacchio quiet.
The defender will mop up any high balls into the box, so Martino's game plan must again revolve around short, sharp balls into and around Messi.
It's how Barca have garnered their success for years, and incessant crossing to no one in particular is patently not working.
Back to basics.