Casemiro was dismissed after a VAR review for putting his hands around Will Hughesâ throat.
Everything you need to know as the World Cup hosts begin their Six Nations campaign
The Easter Road side were without striker Kevin Nisbet for the 1-0 win at St Mirren, settled by Elie Youan's second-half strike. With Hibs already out of the Scottish Cup, they now do not play again until Kilmarnock are the visitors on February 18.