Real Madrid are in a really good shape and again they are busy counting down of matches to lift the trophy, 8 points difference is also a huge gap between them and Barcelona, with the current performance of each club i will advise Barcelona to be patient and try harder next season, talking of Athletic Bilbao I quiet agree with you that this match will be tough because ATLÉTICO MADRID are in the neck Athletic Bilbao for that fourth place, i will only say both ATLÉTICO MADRID and Athletic Bilbao are going to be fighting for the fourth place, the two matches will be very tough, which i see hope for ATLÉTICO MADRID for taking the fourth place because I don't think Athletic Bilbao can defeat Real Madrid at Madrid home, it's possible that ATLÉTICO MADRID can defeat Villarreal but still let with and see who win, the two matches are very hard to predict.
There are still many matches that will be played until the end of the season and thus, if for example Bilbao loses by Real Madrid and Atletico manages to beat Villarreal and that will make Atletico return to fourth place overtaking Bilbao. But, if in the next matches Atletico get bad results again then of course Bilbao will again overtake Atletico because after all, this season Bilbao really has a good performance compared to previous seasons. Therefore, because this season Bilbao has a good trend, then I personally believe that Bilbao will manage to finish in the top four. Also, although Bilbao will play away against Real Madrid later, but I am still very confident that Bilbao will not be defeated by Real Madrid at the Santiago Bernabeu.
Real Madrid winning Atletic Bilbao is likely to happen because the later have very poor away outing this season while the former is a devourer that tears anything that come his way both home or away. Even on their previous meetings, Real Madrid has shown superior strength over their visitor and this year may not be different because their are playing at their peak this time around . On the other hand, it is not certain that Atletico Madrid will be able to win Valencia, but from the abysmal performance of the later, it will be a huge surprise to me if Atletico will spare any point in that match despite playing at away. Coming weekend will show if Atletico will continue to be hopeful of the top 4.