gloucester will face a rugby football union hearing after selecting lock mariano galarza for their game .
the rfu has said galarza should have been ineligible for the match .
in a statement , the rfu said ` in the aviva premiership rugby match against sale sharks on march 29 , gloucester rugby breached aviva premiership rugby regulation 3.3 -lrb- a -rrb- by selecting a player -lrb- mariano galarza -rrb- who did not hold effective registration for gloucester rugby .