Juventus lost their balance so they can no longer put pressure on Inter Milan like at the start of the season and even now they have to lose their position in second place because in the last 3 matches they couldn't win and that gave Ac Milan the opportunity to overtake them. and AC Milan managed to take advantage of that very well.
Actually, things like this are what a team is worried about, yes, they will experience a decline at the end of the season and that will make them unable to compete anymore. Juventus experienced this this season which made them have to give up the title this season. However, they also still have to focus, because even though they cannot become champions, at least they can be in the top 4 of the standings at the end of the season and win a ticket to go to the Champions League next season. Their current position is not completely safe, so they have to keep giving their best, especially to win again after they failed to get it in the last few matches. I'm sure they can secure their position in the top 4 of the standings.
For the Italian teams at the moment, they'll be focusing their strength on the domestic Serie A league and they ought to be doing excellently well in it. Especially Juventus, they've even had a greater chance of being far ahead in the standings than the likes of Inter Milan because for others, after the league games, they'd still have to play the continental tournament and this will definitely affect player's physical capabilities too. Although, inasmuch as a weighty gap is expected of them, Inter Milan has made it difficult because they've also been in their best form.
At the same level time, it'll not be hard to stay in shape to earn a ticket to next season's European contests. They've been able to play resiliently and the results so far is fit to help them earn this ticket but the difficulty they may face this season is the trophy of the Serie A, the top contenders won't let it slip away from them, they're in their own way and end putting streanous efforts to ensure that they get the maximum number of points to keep the gaps and help them win the trophy. There's really no time to make a difference but they themselves know it's not going to be as easy as it ought to be considering the intensity in games this season.
Inter are ahead with a reasonable point gap and undeniably, they're are proving to keep up with consistencies which if met, Juventus no matter what won't be able to catch up to them. Inter are no longer faced with the European contest and so for inter Milan and Juventus, they've still got extra time to prepare ahead for the league games. Against Atletico Madrid, Inter Milan did well to stay in the game but it wasn't just well enough to help them advance in the contest. They've gained enough grounds this season and it's profitable to them considering how well and useful their position has been and will be for them in subsequent games and seasons too.