The winners will face either Borussia Dortmund or Paris St Germain, who meet in the second semi-final on Wednesday.
Athletes expressed their condolences, including UFC fighter Conor McGregor.
The cap would limit how much clubs can spend in a bid to prevent the super-rich teams from dominating the league.
Reigning champions Manchester City have 73 points but have two games in hand.
Inter, who have lost only once in the league this season, hold a 17-point advantage over second-placed Milan with five matches remaining.