La Liga's top two meet in an eagerly anticipated match at the Vicente Calderon on Saturday as Atletico Madrid host champions Barcelona.
Gerardo Martino's Barca are top of the table on goal difference alone, and their opponents this weekend have displayed marginally better recent form in the league.
Atletico have taken maximum points from their last five games, keeping four clean sheets and seeing striker Diego Costa score six goals in the process.
Barca suffered their only league defeat of the season to date when losing 1-0 to Athletic Bilbao at the start of December, but have bounced back by taking nine points from nine since then and are boosted by Lionel Messi's return from a hamstring injury.
Messi scored twice after coming on as a second-half substitute in a 4-0 Copa del Rey win over Getafe on Wednesday, and will be looked upon to play a key role against Atletico.
Xavi, who was rested for the Getafe fixture, was delighted to see Messi back on the field ahead of a game he feels could prove crucial in deciding the destination of this year's title.
"It was an impressive return and (Messi) has clearly come back hungry and motivated," Xavi told Barcelona's official website.
"The game against Atletico is vital for the outcome of the league - it might not turn out to be definitive, but a win would lay down a marker."
In the last 20 years, Atletico and Barca have met as the sides ranked first and second in the table on only three occasions, with the men from Spain's capital winning two of those meetings.
Barca claimed the Supercopa de Espana when the teams last faced off, triumphing on away goals following a 0-0 draw in the second leg at Camp Nou.
Prior to the first leg of that tie in Madrid, which finished 1-1, the Catalan giants had won their last six games against Atletico.
In addition to welcoming back Messi, Barca are also expected to have Neymar available following a bout of gastroenteritis, while another forward, Pedro, is in fine form, scoring five goals in his last four appearances.
Atletico midfielder Koke has warned his team-mates not just to focus on FIFA Ballon d'Or candidate Messi.
"If he plays we have to be careful because he is the best in the world but Barcelona have great footballers and we must be aware of them all," said the midfielder, who scored the winner in Atletico's 1-0 victory at Malaga last weekend.
"It will be a very important game because the top two teams in the league play, (but) it is just another game and the whole second half of the season is to come.
"We know that to date it is the most important game."
Defender Diego Godin is a doubt for Atletico after picking up a thigh problem against Valencia in the Copa del Rey on Tuesday, while Mario Suarez (knee) is also likely to miss out.
|Coach: D. Simeone|
for David Villa 77'
for Tiago 83'
|Cafu: Resurgent Brazil can challenge world´s best|
|Klopp thrilled with Coutinho|
|Manchester United replace Real Madrid as world´s richest club|
|Madrid squad annoyed by defeats - Zidane wants more energy after latest loss|
|Casemiro rues more misery for Madrid against Celta|
|´Job done, let´s go home´ - Klopp happy to avoid extra time with narrow Plymouth win|
|FA Cup Review: Southampton leave it late to beat Norwich|
|Real Madrid 1 Celta Vigo 2: Aspas and Jonny extend Madrid winless run|
|Plymouth Argyle 0 Liverpool 1: Rare Lucas goal sees Klopp´s men through|
|Manchester City in La La Land as Schalke toil underground|
|Cameroon 2 Guinea-Bissau 1: Ngadeu-Ngadjui completes comeback to send Broos´ men top|
|Monaco confirm signing of Ajax teenager Antonucci|
|Manchester United´s interest in Griezmann is unsurprising - Simeone|
|Bamford ends spell in Chelsea wilderness with Boro return|
|Louis the great - Luis Enrique explains his and Barca´s debt to Van Gaal|
|Gabon 1 Burkina Faso 1: Spot-on Aubameyang makes his point|
|PSG send Ikone on loan to Montpellier|
|Senegal v Zimbabwe: Cisse wants to live up to favourites tag|
|Ghana´s Rahman leaves AFCON with knee injury|
|Algeria v Tunisia: Mahrez demands improvement in crucial Group B clash|
|Dortmund forward Dembele hits out at Bundesliga refereeing|
|Robben hopes Alonso stays at Bayern amid retirement rumours|
|Asian champions Jeonbuk banned from 2017 Champions League|
|Rakitic still an important player for Barcelona - Luis Enrique|
|Jesus will develop quicker at City - Emerson|
|Always take the weather with you - Spanish snow blights CSKA´s training camp|
|Messi never gave Coach interview, claims father|
|Gotze questions critics but admits to falling short of expecations|
|´Conte can have our title´ - Ranieri wants Chelsea to win the Premier League|
|Tottenham reject Premier League, Bundesliga offers for Wimmer|
|Liverpool sell Ilori to Reading|
|Potential victims in football abuse probe surpasses 500|
|Bonaventura signs new AC Milan contract|
|Messi: Ronaldo has achieved great things|
|Koscielny: Wenger has built men at Arsenal|
|Messi vows to stay at Barcelona ´for as long as they want me´|
|Cafu adamant Neymar will become world´s best|
|I´m just taking a sabbatical - Van Gaal denies he´s retired|
|Not even Gerrard won Premier League - Buttner says he´s not a United flop|
|Samper ignored Wenger as Barca midfielder rejected Arsenal|
|Pleased Pioli wants more from Inter|
|Evergrande boss Scolari dismisses Turan links|
|Klopp seeks legal advice over Matip|
|Marseille complete Sanson move|
|Inter 3 Bologna 2: Candreva prevents remarkable turnaround in Coppa Italia thriller|
|FA Cup Review: Non-league Lincoln stun Ipswich, Burnley and Palace through|
|Gabon v Burkina Faso: Aubameyang says hosts have learned from Guinea-Bissau setback|
|Mali 0 Egypt 0: El-Hadary makes history in stalemate|
|El-Hadary oldest AFCON player ever - 44-year-old Egypt goalkeeper makes history|
|Reus and Gotze on target but Bender injured in Dortmund win|
|Toure shunning lavish China interest to stay at City, says Seluk|
|Rahman´s AFCON in the balance, says Ghana boss Grant|
|Just 14 goals conceded and nine clean sheets - How Vertonghen blow could impact Tottenham|
|Ghana 1 Uganda 0: Andre Ayew hands Black Stars nervy victory|
|Swansea snap up Carroll and Olsson in double swoop|
|All is forgiven? - Costa trains with full Chelsea squad after reported Conte bust-up|
|I would throw myself off a bridge for Luis Enrique - Rakitic dismisses Barca rift rumours|
|Was Juventus´ new logo inspired by tennis star?|
|Smooth sailing for Liverpool in Plymouth? Klopp expects tough test|
|Demichelis re-joins Malaga until end of season|
|Cameroon v Guinea-Bissau: Broos urges new heroes to emerge|
|Boxing champ hits Carragher with Chinese Super League comeback prank|
|Zidane backs Navas and defends Benzema as Madrid aim to bounce back|
|Deportivo bring in Kakuta from Hebei after CSL rule changes|
|Matip could miss eight games without doing anything wrong - Klopp|
|United trigger Valencia´s contract extension|
|Ronaldo returns to Real Madrid´s Copa squad|
|FA fine Sagna for Instagram post|
|Nedved does not foresee more January business for Juventus|
|Rafinha injury blow for Barcelona|
|Villas-Boas fumes at CSL foreign player crackdown|
|Ibrahimovic invaluable to Manchester United youngsters - Rashford|
|Robben rejected China move|
|A-League review: Phoenix rise to the occasion to end Victory´s streak|
|Van Gaal slams English media over treatment at Manchester United|
|Mignolet: Liverpool in better position to win title than in 2013-14|
|Giroud wants Premier League title but understands China temptations|
|Tianjin forced to scrap moves for Costa, Benzema, Cavani and Falcao|
|My goal was better than Mkhitaryan´s - Giroud|
|Pochettino not interested in Argentina job|
|Kane: Tottenham can win Premier League|
|Corinthians dreaming of Drogba - Paulo Roberto|
|Coutinho calls for Liverpool focus|
|Chiellini compares Pogba to LeBron and Bolt|
|Maradona to become Napoli ambassador|
|Mihajlovic furious after Torino collapse|
|Icardi has offers from China - Wanda Nara|
|Pogba can cope with pressure - Ibrahimovic|
|´My half-time words will stay in the dressing room´ - Montella annoyed with AC Milan|