I believe that Porto will be the one that will make the biggest changes, especially because they will change coaches. But, as they are subject to financial fair play by UEFA, they may be somewhat limited in the business they do.
Benfica will at least have to find a clear striker for the squad, and sign full-backs. Hire, or look for the formation, which usually has good players.
Sporting will probably have to at least look for the new striker, but I believe the structure won't change much.
I also think that Porto will be the team that changes the most next season
Sporting will need a new striker if Viktor Gyökeres leaves the team
In fact, do you think he could leave Sporting for another big European club or not yet?
I really wanted Benfica to be able to make good changes to the squad so that next season we can become champions again, but also when we play in the European Champions League we can get good results, for example these days I read that Benfica signed a player from manchester united, the player's name is Álvaro Fernández. but I didn't see this player being very useful at Manchester United
...
But something I like about Benfica is a team that manages to sign a player who is worth little and turns him into a player who is worth a lot of money and then sells him. So in terms of Benfica not wasting money on players, on the contrary, they always make a profit, Benfica are doing well. But in terms of performance in European competitions, we need to improve a lot, every season it seems that Benfica cannot handle European competitions well, while Porto does well in European competitions.
Álvaro Fernández is only 21, he's a very young player who could do well at Benfica
He has already played for Real Madrid U17 and M. United, and he can try to make the most of the chance to be in a good league and get a chance to play
I'm curious to know if Di Maria will continue to play for Benfica