Girona must immediately restore their current performance if they want to remain in the top 4. Meanwhile, regarding Atletico Madrid, there are only 3 difficult matches that Atletico Madrid will face in the remainder of this season, namely against Girona, Bilbao and Real Sociedad. Meanwhile, the remaining matches can actually be said to be quite easy, such as against Osasuna, Getafe, Celta, Mallorca, Villareal and Alaves.
So I think Atletico Madrid will find it quite easy to return to the top 4.
Because Bilbao also has the chance to lose in the next match against Real Madrid. And that's when we will see Atletico Madrid return to 4th place.
Girona are still safe in top four and their position is better than Atletico Madrid. You are only partially right about remaining matches of Atletico Madrid because you forgot that they will have to play in Champions League too. With affects from Champions League, Atletico Madrid have risk to lose concentration on their matches in La Liga around two quarter final matches, and they potentially can lose points too.
If they lose points, it will be harder for them to return to top four. Girona are still in top four and they only have La Liga to focus on so at least they are not at high risk to end this season out of top four like Atletico Madrid.