It depends. In some prior Olympiads, FIFA mandated that teams release players (2008 & 2012) and in others it did not (2016). I don't think it is yet clear what FIFA will require in 2020, although it is not on the official calendar.well the tweet is about US players....Haak/ sands. Taty already qualified with argentina. the actual olympics i think they are forced to but this is only qualification.