At this stage, it all depends on Atletico Madrid. They need to consistently play the remaining matches and not lose the game to Barcelona. In addition, there is a chance that Barcelona will not be able to beat Real Madrid. It would be better for Atletico Madrid to have Barcelona and Real Madrid draw.
I strongly doubt Atletico Madrid will be consistent for the remainder of the season, they've still got tough fixtures ahead including one against Barcelona, However, be eliminated from all other competitions might help the concentrate and prepare better.
If Atletico Madrid can score 6 points against Sevilla and Barcelona, they will win the title this season. I think so. Because without these two opponents, the rest of the opposing teams are not very strong. And if Atletico Madrid can beat Barcelona, Barcelona will be out of contention for the title.