Track conditions will decide if Mr O'Ceirin will use the Moonee Valley Gold Cup as a lead-up start to the Melbourne Cup.
A possible thunderstorm is forecast on Friday night with drizzle early on Saturday and trainer Ciaron Maher said he will make a final decision on race morning.
Maher explained Mr O'Ceirin had performed below expectations on firm tracks with his better performances coming on surfaces that had some give in them.
Should Mr O'Ceirin miss out on Moonee Valley, he could instead use the Bendigo Cup next Wednesday as a lead-up race to the Melbourne Cup.
However, Maher would not be worried about sending Mr O'Ceirin into the Melbourne Cup without another start, although track conditions could be a concern for the trainer.
"The distance will be no trouble for him at all," Maher said.
"He's been in work all year and is very fit.
"The owners may want to roll the dice and run him in the Melbourne Cup.
"We'll wait and see what the weather does, otherwise he could be kept for the Queen Elizabeth."
Mr O'Ceirin is 28th in the order of entry for the Melbourne Cup.
A penalty for winning the Moonee Valley Cup would see Mr O'Ceirin safely in the Melbourne Cup field with at least six runners above in the order of entry expected to miss the race.