@Hoofenballen that's a great first season with Atletico, especially considering the defensive personnel aren't quite what they used to be! You even scored over 90 goals in the league which is awesome.
I did a two year save with them recently and might go back to it soon.
I don't think you need to have a massive squad overhaul to push on and challenge the top two. Barrios looks like he could be a good squad player and could develop well. There are also several decent loan players due back - Joao Felix, Camello if he got enough game time, Samu Omorodion if his variable potential is good in your save, and Javi Serrano. Serrano and Camello would be short term options or could get you a decent fee. Rodrigo Riquelme was ok for me when he played - low wage demands and happy for a fair bit of bench time.
There are also lots of expiring contracts for older, big wage players such as Witsel, Azpi, Vitolo, Hermoso and Savic which would free up a fair bit of funds! Guido Rodriguez & Oliver might be available on frees if they haven't already been snapped up - I picked them both up on frees and they have been solid - plus Oliver is HG at Atletico. I did also sign de gea on a free to sell grbic.
I didn't sell him as I had him in previous FMs and he was fantastic and just can't convince myself to sell him... but Saul is worth selling as his wages are so high for a very average player now, and Depay could bring in a lot of money - I had offers of 65-75mil for him from Saudi clubs. I held off on selling him as Griezmann was out for 4-5months.