West Ham defender Vladimir Coufal and two other players have been sent home from the Czech Republic camp.
The Czech Football Association said the players had "fundamentally violated the internal rules of the national team on Saturday night".
It added: "They have left the national team camp with immediate effect."
The Czech Republic will qualify for Euro 2024, to be hosted by Germany, if they avoid defeat to Moldova in their final qualifying match.
Coufal, 31, joined West Ham from Slavia Prague in October 2020 and has made 101 Premier League appearances.
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