Luis Enrique's men little room for error in their quest for a third straight La Liga title.
Barca trail league leaders Real Madrid by a point, but have also played two games more than their title rivals, leaving Luis Enrique's men little room for error in their quest for a third straight La Liga title.
Enrique has been the fall guy for Barca's disastrous showing in a 4-0 thrashing in Paris on Tuesday with fans, media and even the club's players criticising his tactical set up.
Key midfielders Sergio Busquets and Andres Iniesta, who were overrun by PSG's pace and power, insisted Barca's problem was not one of attitude one but being outplayed thanks to PSG boss Unai Emery's master plan.
Even Lionel Messi was off colour as his mistake led to PSG's second goal, but Javier Mascherano claimed the five-time World Player of the Year is the only Barca player who can't be questioned.
"Leo is indispensable and, yes, the rest of us are expendable," Mascherano told Barca magazine.
"He is unique. We are talking about the best player in the history of this sport without any doubt."
Fortunately for the Catalans, they couldn't have picked better guests for a time of crisis as Leganes travel to the Camp Nou having been dragged into a battle against relegation by a 12-game winless run.
Ironically, Enrique had rotated heavily throughout the first two months of the year to ensure Barca were not physically worn down before their trip to the French capital.
Despite a first free midweek of the year to come after Sunday, though, Enrique is expected to ring the changes again with Lucas Digne, Rafinha, Ivan Rakitic, Denis Suarez and Arda Turan all in contention to come into the side.
Madrid can open up a four-point gap at the top on Saturday when Espanyol visit the Santiago Bernabeu.
The European champions enjoyed contrasting Champions League fortunes in midweek as they came from behind to beat Napoli 3-1 and could have even more firepower available with Gareth Bale in line for his return after three months out with ankle ligament damage.
Real boss Zinedine Zidane resisted the temptation to rush the Welshman back into action after he returned to training last weekend, but is expected to at least appear off the bench.
Espanyol's hopes of European football next season were punctured by a first home defeat since September to Real Sociedad last weekend to leave them four points off the top six.
And there is little in Espanyol's recent record against Madrid to give former Watford boss Quique Sanchez Flores's men hope as they have lost their last nine against Real and haven't won in their last 20 meetings.
Sevilla can leapfrog Barca into second for at least 24 hours as they warm up for their Champions League clash with Leicester City on Wednesday by hosting the on-form Eibar, who harbour European ambitions of their own.
Atletico Madrid could also have a return to Champions League action in mind when they travel to a Sporting Gijon side suddenly eying survival after their first win since December at Leganes last weekend.
Any slip up by Atletico could be pounced on by Sociedad, who trail Diego Simeone's men by just a point in the battle for fourth, and host sixth-placed Villarreal in a huge clash for the final Champions League place on Sunday lunchtime.
Granada v Real Betis (1945)
Sporting Gijon v Atletico Madrid (1200), Real Madrid v Espanyol (1515), Deportivo la Coruna v Alaves (1730), Sevilla v Eibar (1945)
Real Sociedad v Villarreal (1100), Valencia v Athletic Bilbao (1515), Celta Vigo v Osasuna (1730), Barcelona v Leganes (1945)
Malaga v Las Palmas (1945)