Top mare Ortensia may not be a challenger in Perth?s Group One Railway Stakes if she receives an official invitation from Hong Kong.

After finishing strong behind Strawberry Field in the Herald Sun Stakes on Melbourne Cup day, the mare is a real contender for the international races.

Trainer Tony Noonan will hold off all plans until tomorrow to see if she will be one of four Australians competing in the Hong Kong Mile.

If she does receive an invite, Noonan will need to prep Ortensia for the 1200m sprint and may have to miss the Perth Racing Carnival altogether.

If possible, Noonan will first run the mare in Saturday week?s Railway Stakes and then head over to Hong Kong.