CNN) -- Barcelona coach Tito Vilanova has returned to the Catalan club's training ground just two weeks after undergoing surgery to remove a tumor from his throat. Vilanova suffered a recurrence of a tumor on his parotid gland -- located at the back of the mouth -- and was released from hospital on December 22. The former assistant coach, who replaced Josep Guardiola in June, returned to training on Wednesday ahead of the Spanish league leaders' derby match with Espanyol on Sunday. Vilanova also dropped in on the Catalan national team -- featuring nine Barca players -- as it prepared for a friendly match with Nigeria. Transfer window offers rich pickings Transfer window offers rich pickings Lionel Messi's record year Lionel Messi's record year Messi moves past Pele milestone Messi moves past Pele milestone The Real Ronaldo The Real Ronaldo Schmeichel's Champions League tips Schmeichel's Champions League tips Blog: Barcelona's Vilanova coach of the year? "The manager ... led the team's second training session of the year," read a statement on the club's official website. "This morning, Vilanova stopped by the Ciutat Esportiva to meet with the Catalan players ahead of this afternoon's Catalonia vs. Nigeria match." Barca president Sandro Rosell said last weekend he hoped Vilanova would be fit to return to work in two-to-three weeks. Despite not being recognized by football's global governing body FIFA, a squad made up entirely of Catalan players occasionally plays exhibition matches. The team, led by Dutch former Barca player and coach Johan Cruyff, was held to a 1-1 draw by Nigeria at the Camp Nou. Midfielder Sergio Gonzalez, without a club since being released by Levante in 2011, gave the Catalan team the lead from the penalty spot after three minutes. But Nigeria earned a draw when U.S.-born Portland Timbers striker Bright Dike equalized after 55 minutes. Super Eagles coach Stephen Keshi is preparing Nigeria for this month's 2013 African Cup of Nations in South Africa, where the two-time tournament winners have been drawn in a group with 2012 champions Zambia, Burkina Faso and Mali. Barca goalkeeper Victor Valdes picked up an injury in the match which will see him sit out training on Thursday. Vilanova's team, under the temporary guidance of assistant Jordi Roura, is looking to continue a run which saw them pick up a record 16 wins from their first 17 league matches of the season. The Espanyol tie will see Argentine star Lionel Messi take to the field for the first time this year, after a record-breaking 2012 which saw him score 91 goals. Barca currently lead second-placed Atletico Madrid, who face Mallorca on Sunday, by nine points, with archrivals Real Madrid a further seven points back. Cruyff described Real's start to the season as a "failure", while also questioning coach Jose Mourinho's decision to drop Spanish international goalkeeper Iker Casillas. "At this stage of the season Real Madrid being 16 points behind Barcelona can only be called a failure," Cruyff was reported to have said by Spanish newspaper Marca. On Mourinho favoring Antonio Adan over World Cup winner Casillas, Cruyff commented: "You don't lose your place overnight." Real host Real Sociedad on Sunday.