UEFA has suspended Fenerbahce player Volkan Sen from club competitions until the end of December for pushing a referee.
Liverpool and Manchester United have each been fined €40,000 (£30,565), half of which is suspended, by UEFA's control, ethics and disciplinary body.
Liverpool attacker Divock Origi has said that he took a risk playing in last week's Europa League final against Sevilla.
Liverpool's failures in Europe are as much a part of their history as their famous wins, writes Steven Kelly.
Kenny Dalglish says everyone at Liverpool is behind Jurgen Klopp, despite Liverpool's two losses in cup finals this season.
UEFA has opened the disciplinary cases after fans fought in a poorly segregated section of the stadium before the Europa League final on Wednesday.