Madrid’s La Liga title challenge could come down to a single player – and a single victory against Atletico Madrid, who are currently eighth in La Liga.
Real Madrid are currently ninth in La League, just one point above Real Sociedad.
The Spanish side face Atletico on Sunday, and the tie is all but certain to be decided by the final score.
However, despite being in fourth place, Madrid’s form has been impressive – with the La Liga champions having taken a comfortable 10 points from their opening five matches.
And they are on course to reach the Champions League quarter-finals, having beaten rivals Barcelona 3-1.
They will be hoping to avoid a repeat of their Champions League defeat by Atletico, which took them to the quarter-final stage in the last 16 in 2010.
Real Sociedada will also be hoping that they can keep up their remarkable form.
They’ve won five of their six games, and are unbeaten in their last six away games.
Atletico were also knocked out of the Champions league by Atalanta in the quarter finals in 2014.
After winning their opener, Real Sociead were level on points with rivals Barcelona, but the hosts had the better of the first half.
They were in the ascendancy when Sergio Ramos hit a low shot from outside the area that deflected off the crossbar and into the bottom corner.
It took Real Sociesad until the 65th minute to level the score, as Ramos’s cross was headed away by Javier Hernandez.
Then, in the second half, Atletico came back to win it 3-2.
With Madrid sitting three points adrift of the play-off places, they are keen to take their form to the next level and try to extend their unbeaten run to five games.
The draw will be a crucial one for Real Socyad, who will need to win their remaining fixtures to ensure that they are able to make it to the Champions Cup semi-finals.
They have played two more matches than Atletico.
Real Oviedad have lost just once in the Champions’ League, but have won six of their eight matches away from home.
They were beaten by Bayer Leverkusen in the Europa League last season, and were knocked out in the round of 16 by Barcelona in the 2014-15 Champions League.