For the second time in as many years the NRL could be forced into staging a semi-finals double header if the Sydney Swans lose their qualifying final to Fremantle this weekend.

The NRL are keen to avoid another finals double header after the disappointing crowd that attended last year, however they might have to rely on the Swans knocking over Fremantle to do so.

Peta Hiku puts on a fend during the second half of the double header at Allianz Stadium last September. Credit:Getty Images

The only way the NRL will be forced into playing another double header at Allianz Stadium in week one of the finals is if four Sydney teams earn home finals and the Swans lose this weekend.

The teams that finish the regular season in first, second, fifth and sixth will play home finals in week one of the NRL series, with all Sydney teams to play at ANZ Stadium and Allianz Stadium.