If it is a draw, Madrid will take a step forward or if Barca win they will take the top spot , anything can still happen
Top three have all gotten three points and the match between Atletico Madrid and Barcelona will become hottest. It will be a decisive match for two clubs. Atletico Madrid will create a big gap if they win and take three points. Barcelona must win the match and if this clash ends with a draw, Real Madrid can smile.
Real Madrid have to take three points in their match and I don't think they will have too much resources and energy to fight for both La Liga and Champions League. They are in complicated conditions: in Champions League, Chelsea have some supports before the second leg and it will be held in Stamford Bridge. In La Liga, they are behind other two clubs. Zidane and Real Madrid have been in complex situation and any decision will be a big choice for them.
The 3 points against Valencia wasn't the easiest one but it was worth it and it probably showed the team what's still to come in the remaining fixtures, neither of those fixtures are going to be easy, the cannot afford to drop any more points and a win against Atletico Madrid next weekend will steer things in the best direction while hoping for a drop of points from Real Madrid.
My view from the game is that Barcelona still need to work a lot on their defense, more than ever needs a real centre forward, Pedri is a great work in progress, and De Jong is definitely the future of Barcelona's midfield.