Barcelona coach Gerardo Martino said his team could be out of the La Liga title race should they lose at Real Madrid on Sunday.
The champions trail their rivals by four points heading into the El Clasico at the Bernabeu, with Atletico Madrid sandwiched between the two sides three points behind Carlo Ancelotti's league leaders.
With just 10 fixtures remaining in the domestic season, Martino feels it is now or never for Barcelona.
"This is probably our last opportunity to keep ourselves in the fight for the title," Martino said on Saturday.
"After this game there will be nine (matches to play), and it's not the same as closing up on a one point gap than four or seven is.
"At this stage, teams - mainly the ones playing for the title - do not normally make mistakes."
Martino identified Real's consistency as the defining factor in their rise to the top of the table, and not any difference in quality between the top two in the Spanish top flight.
"Both sides face this Clasico knowing perfectly well what they have to do," he said.
"The only difference up until now is that Real Madrid have been consistent since the last Clasico and we haven't.
"The quality of both teams is clear. The thing is we haven't been as consistent as them so that made us drop points and therefore drop down the table. But this is not a matter of quality at all."
Martino also said he had no qualms about letting Brazilian starlet Neymar know how good he was, ahead of Barca's visit to the Bernabeu.
"Neymar was great against Manchester City, and secondly I will reaffirm what I've said plenty of times - he's amongst the five best footballers in the world," he said.
"I don't need one game or half of it, not even 10 (minutes), to believe his qualities. So within my powers, I'll try to make him not think that he's just one more player in the squad because he's not."
|22||Á. di María||35'|
|7||Cristiano Ronaldo||55' 86'|
|9||K. Benzema||20' 24'|
|Coach: C. Ancelotti|
for K. Benzema 66'
for Á. di María 85'
for L. Modrić 90'
|Porto invite Euro elite to help raise millions for migrants|
|Dortmund legend Dede backs Tuchel to succeed|
|Robben out for four weeks|
|Turkey v Netherlands: Terim expecting hostile atmosphere for crunch clash|
|Wales v Israel: Euro 2016 beckons for Coleman´s history boys|
|Gala: No extra payment for Grosskreutz|
|Increase Bundesliga´s TV rights or be left behind - Rummenigge|
|Kane: I´m no flash in the pan|
|Perez: United showed inexperience in De Gea saga|
|Milligan: Socceroos wary of Tajikistan|
|Conte wants more players like Pelle|
|OFC World Cup Qualifying Review: Samoa to meet Tahiti in next round|
|Krychowiak stayed at Sevilla because of Emery|
|I never considered Bayern exit - Gotze|
|Balotelli ´not in good condition´, Milan must improve - Mihajlovic|
|Robben slams ´stupid´ Martins Indi|
|Robben laments injury blow|
|Euro 2016 Qualifiers Review: Bale edges Wales closer, Iceland dent Netherlands´ qualification hopes|
|De Bruyne relieved to ´boss´ Bosnia-Herzegovina|
|Blind furious after nightmare debut|
|Coleman sees shades of Charles in Bale winner|
|Conte only concerned about Italy winning|
|Mauritania v South Africa: SAFA to investigate Masilela no-show|
|AFC World Cup Qualifying Review: Qatar hit 15 in Bhutan rout|
|Belgium 3 Bosnia-Herzegovina 1: De Bruyne shines in straightforward victory|
|Cyprus 0 Wales 1: Bale winner takes Wales one step closer|
|Netherlands 0 Iceland 1: Sigurdsson winner caps difficult first game for Blind|
|Italy 1 Malta 0: Pelle spares wasteful Azzurri|
|Balotelli stars in Milan friendly win|
|Bhutan thrashed 15-0 by Qatar in qualifier|
|Rwanda v Ghana: Gyan doubt gives hosts hope|
|Tanzania v Nigeria: Enyeama out of AFCON qualifier|
|Valdes and Berahino included in Premier League squads|
|Costa Rica v Brazil: Dunga´s men return after Copa disappointment|
|Spain v Slovakia: Azpilicueta eyeing important revenge|
|Adebayor left out of Tottenham squad list for league and Europe|
|San Marino v England: Place in history books beckons for Rooney|
|Germany can cope with Reus absence - Low|
|Bayern offer aid to refugees in ´training camp´|
|BREAKING NEWS: Welbeck ruled out for months after knee surgery|
|South Korea 8 Laos 0: Son leads the way in rout|
|Australia 5 Bangladesh 0: Socceroos surge to emphatic win|
|Japan 3 Cambodia 0: Hosts pick up first qualifying win|
|Rudiger aiming to nail down Euros spot after Roma move|
|Melo happy to join Inter at last|
|Hernandez thanks Ferguson after United departure|
|Chung: AFC has compromised FIFA election|
|Wales the new best of British|
|Reus out of Germany qualifiers|
|Chile v Paraguay: Vidal missing for Copa champions|
|Ghedin: Anything is possible for Malta|
|Pogba will be worth €100m - Marotta|
|England can win Euro 2016 - Hodgson tells players|
|Conte unsure over Balotelli future|
|Portugal - France Preview: Deschamps aiming to correct mistakes|
|Martial never the same again - Mangala|
|Copa del Rey Review: Racing fall at the first|
|Shelvey dismisses talk of England snub|
|Galatasaray unable to play Grosskreutz|
|Faroe Islands v Northern Ireland: O´Neill preaches patience ahead of Euro double-header|
|Levy slams ´wholly inappropriate´ West Brom after Berahino chase|
|Panama v Uruguay: Visitors without Suarez and Cavani|
|Captaincy won´t change me - Robben|
|Liverpool sign Brazilian youngster Allan|
|PFA expects swift Berahino resolution|
|Argentina v Bolivia: Mascherano backs ´very special´ Messi|
|´I do not know if I´m worth €80million´ - Martial shocked at price-tag|
|Afellay suspension reduced|
|Noble red card rescinded|
|Portugal v France: Deschamps aiming to correct mistakes|
|Bahebeck given the all clear|
|Germany v Poland: Muller out to settle the score|
|Gibraltar v Republic of Ireland: Keane counting on McCarthy and Walters|
|Georgia v Scotland: Tbilisi trip has must-win feel for Robertson|
|Juve still the team to beat - Hernanes|
|De Gea will remain professional, says team-mate Mata|
|Berahino given extra time off following strike tweet|
|´No excuses´ as Costa seeks to kick-start season|
|I´m not like Messi or Ronaldo – Hazard|
|United States v Peru: Klinsmann out to ´prove a point´|
|Martinez unsure when Cleverley will return|
|France set for Russia friendly ahead of Euros|
|Former Manchester United forward Berbatov joins PAOK|
|De Gea must play to earn Euro 2016 spot – Del Bosque|
|Cahill thrilled to lead Socceroos|
|Wijnaldum urges patience with new-look Newcastle|
|Reid praises Stones´ professionalism|
|Mexico v Trinidad and Tobago: Islanders hoping to build on Gold Cup display|
|Choosing Brazil over Spain was easiest decision, says Rafinha|
|Galliani hails ´changed´ Balotelli|
|OFC World Cup Qualifying Review: American Samoa notch second competitive win|
|Canada v Belize: Hosts look to stay calm|
|Carragher surprised by ´big´ Martial price|
|No pressure on Rodgers - Rush|
|No Benzema, no Cavani - Arsenal ´can´t compete´ says Sol Campbell|
|FFA muzzle Postecoglou after pay dispute criticism|
|Celtic complete Simunovic signing|
|Joaquin: I´m as happy as a little boy|
|Navas given time off by Costa Rica|
|Martial unfazed by prospect of United pressure|
|Ramos urges De Gea to overcome transfer woe|