ap mccoy 's last chance of a national winner before he retires has evaporated after benvolio , his intended mount in this afternoon 's coral scottish national at ayr was withdrawn .
ap mccoy finished fifth on shutthefrontdoor in the grand national , but will not ride in the scottish national .
mccoy 's final quest for national glory began in the irish version of the race when sixth on cantlow on easter monday .
the soon-to-be-crowned 20-time champion was then fifth on favourite shutthefrontdoor in last saturday 's grand national .