La Liga leaders Real Madrid face one of their toughest tests since embarking on a 22-game winning streak back in September when they start 2015 with a trip to Valencia on Sunday.
Los Che have reason to be optimistic in the new year with a return to Champions League football for next season top of their agenda.
Valencia sit fourth, a solitary point above Sevilla, Villarreal and Malaga, but demonstrated their financial advantage over the other Champions League hopefuls following Singaporean businessman Peter Lim`s recent acquisition of the club by splashing out 25 million euros (£19.4 million, $30 million) on Argentine international midfielder Enzo Perez this week.
"I have the greatest expectations of making a good start here," Perez said as he was presented to the Valencia fans on Friday.
"I hope that this new project at Valencia grows, and that 2015 will be a happy year for us all."
Perez is expected to make his Mestalla debut against a Real side still shorn of Luka Modric through injury.
Sergio Ramos is also a serious doubt having played with a calf injury as the European champions ended 2014 by collecting their fourth trophy of the year in the Club World Cup against San Lorenzo a fortnight ago.
Unusually the opening of the transfer window has sparked rumours of possible departures from the Santiago Bernabeu rather than big money signings with Gareth Bale linked with a move to Manchester United.
However, the Welshman, who scored in his third final for Los Blancos with his 11th of the season in the Club World Cup final, has dismissed suggestions that he could leave the Spanish capital after a remarkably successful 18 months since joining from Tottenham Hotspur.
"It has been a fantastic year for me. I wanted to come to Real Madrid to win titles and work alongside the best players and that is exactly what I have done in a single year," he told the club`s website.
"Hopefully we can keep improving, keep winning titles and I can keep showing my best."
Barcelona start the year just a point adrift of Real at the top, but having played a game more.
The Catalans also face a potentially tricky trip away to David Moyes`s Real Sociedad on Sunday and have had little time to prepare for the game as a group following the Christmas break.
Lionel Messi, Neymar and Dani Alves only returned to training on Friday, while the latter remains a doubt due to a hamstring injury.
"Every game now is a chance to cut the gap," said Barca goalkeeper Claudio Bravo, who will be facing the club he played with for eight years before joining Barca in June.
"It depends on us playing well and, sooner or later, our rivals will drop points."
Moyes, meanwhile, has urged his players to summon the spirit and performance levels which saw them defeat Real and Atletico Madrid at home this season before his appointment.
"We respect Barcelona because they are a very good team, but they are coming to San Sebastian and we have to show them this is not an easy place to come and win," said the Scot.
"My players have already shown that they are capable of beating Barcelona."
Champions Atletico Madrid host Levante in the first La Liga match of the year on Saturday, but Fernando Torres will not be available to mark his return to the Vicente Calderon as his move from AC Milan cannot be formally completed until the Italian transfer window opens on Monday.
Fixtures (all times GMT)
Atletico Madrid v Levante (1500), Sevilla v Celta Vigo (1700), Elche v Villarreal (1900), Deportivo la Coruna v Athletic Bilbao (2100), Malaga v Almeria (2100)
Getafe v Rayo Vallecano (1100), Valencia v Real Madrid (1600), Espanyol v Eibar (1800), Real Sociedad v Barcelona (2000)
Cordoba v Granada (1945)