Madrid, Feb 7 (IANS): FC Barcelona face a vital away game Sunday when they travel to play Athletic Club Bilbao in a La Liga football match at the San Mames Stadium.

Following their defeat away to Real Sociedad in the first match of 2015, Barcelona have won every game they have played.

But they approach this match knowing that anything other than a win will do serious harm to their league title hopes, reports Xinhua.

Barcelona have the luxury of playing 24 hours after the Madrid derby between defending champions Atletico Madrid and league leaders Real Madrid and depending on the result of that game, could close to within just one point of Real at the top of the table.

Barcelona coach Luis Enrique has no serious injury worries for the game.

Brazilian striker Neymar has been in excellent form, forming part of an attacking trio involving Luis Suarez and Lionel Messi and he is expected to lead the attack again. Suarez has struggled to score since his arrival from Liverpool but has contributed crucial assists to his companions' goals.

Neymar is also in the news as his transfer from Brazilian club Santos to Barcelona in 2013 is being investigated by the court. But it remains to be seen how much off the field issues will affect his on-field performance, since he has been in sparkling form so far.

Athletic meanwhile go into the game without injured midfielder, Ander Iturraspe, who will miss between four and six weeks with a knee injury.

He will be replaced by either Mikel San Jose or Benat Etxeberria for the game.

"We know we are going to have to run more than they are and we have to make the game difficult for them to have any hopes of winning," Athletic coach Ernesto Valverde said.

Athletic will be boosted by last weekend's 2-1 win away to Levante and will once again look to striker Aritz Aduriz to be their main attacking threat.