Who was the first player sent off during a soccer match?

Plácido Galindo was the first player to be sent off in a World Cup match, playing for Peru against Romania in a 1930 match officiated by Alberto Warnken. Although physical red cards were introduced from 1970, they were not put in practice until the 1974 World Cup, when referee Doğan Babacan sent off Chile's Carlos Caszely during a match against West Germany.