Changing Virgin flight on the day

Hi all,

My partner is a swim coach and is in Brisbane for nationals. His last event is a heat on the 24th of April in the morning, and he is booked to fly home on the 25th.

However, if his swimmer does not make the finals that night he will be all done by midday on the 24th.

Will he able to change his flight to one on the 24th on that day if there are available seats? He is flying with Virgin.

Thanks!