Atletico Madrid is indeed the main competitor between Barcelona and Real Madrid. They (Real Madrid and Barcelona) are always in the shadow of Atletico Madrid. Once they make a data error, it is not impossible that Atletico Madrid will take over their position in the standings. It's just that they are one step behind the two clubs, but their potential to bring them down is very high.
Really? Are we sure that they are going to be that good, I feel like they may have started off great but they are going to end up losing a bit of money if you ask me. This is my idea though and maybe I will be wrong but that's just what I believe. Maybe I will be wrong and that's not going to be something they will do.
This is not going to be an honest situation to be in for sure, because they started so well and I do not have any hopes for them anyway, so it may not look realistic to many. But I believe Barcelona will recover, and Real is doing awesome, which means they will be the top 2 again, even if Barcelona fails to win it, I do not think they will leave the second position.
Don't forget they are also still shadowing in the 3rd position even though they are quite far away for Madrid but they can still be said as competitors for Madrid and Barcelona and although last season they played quite badly but I still feel they can still at least hinder a little in the title race .
We know that last season apart from them being too focused on all the schedules so that their rotation was chaotic, player injuries were also a hindrance. now just waiting for Simeone's steps to make this better then it's not impossible that they will become quite a troublesome challenger.