The only way for milan to be consistent is to bring in some new players to back up other players, especially their strikers who are indeed quite old and also prone to injury, so far giroud, ibra and leao are their mainstay in the front lines, and we know that ibra and giroud are players who have a long history of injuries. Milan are currently approaching Pietro Pellegri to become a substitute for ibra and giroud but reportedly only as a loan player without a permanent purchase agreement by Milan.
I would say that getting subs is always a good idea even if you have young players. I mean for example Liverpool has one of the meanest wingers in the entire world (and so does PSG) but does that mean they have no subs for salah and mane? Of course they do. It is more about the heavy schedule, it is looking more and more like teams are playing a ton of games, it is possible that teams could actually have a lot more games in the future as well because more games equals more money and that will require a deep roster.
However for just time being, if we go back to Milan situation then I could say that they are doing fine so far and I do not see a reason to worry. They have 2 old players that's true, but what are the chances of both of them getting injured at the same for a long period of time? I suspect it could happen but that would be for very little amount of games most probably. A loaned player is WAY more than enough.
