In one of the anomalies of the NRL's finals system, the Storm and Panthers are facing the daunting reality of being on the same side of the draw if one of them lose this week.

It means that if either Manly upset Melbourne or South Sydney shock Penrith, the two top-ranked teams would be on a collision course to clash in a preliminary final.

In turn, a win from either the Sea Eagles or Rabbitohs would open up their clearest possible path to the grand final, as well as the bottom-four teams that land on their side of the draw.

That comes after 2021 being the first full season where the top two teams have dropped only six games between them since Manly and Canberra in 1995.

Incredibly the Storm and Panthers have only lost a combined 12 games in the past two seasons when including the shortened 2020 competition, with four of those matches against each other.

But that could all count for nothing when the finals kick off.

Praised by most for its simplicity, the NRL's finals system is the only one in which the possibility of a first versus second meeting in the decider can be taken away in the first week.

Under the much-maligned McIntyre system that preceded the current set up, it was impossible for first and second to meet before the grand final.

Often derided for its complicated format and the risk of a top-four team bowing out early, the system designed by Ken McIntyre in 1931 offered the maximum possible grand final combinations.

The top-five and top-four systems the NSWRL used before 1995 ensured the possibility of the best two teams meeting in the grand final regardless of first-week results.

There are other big consequences from this week's qualifying finals, particularly for Penrith and Souths.

Already being forced to fly to Townsville this week, it appears likely the loser will be back on the road next week with the NRL set to host semi-finals in Mackay.

If the teams advanced to week three, they would then come up against the winner of Melbourne and Manly who have not had to leave their Sunshine Coast base since the start of the finals.

"That all goes into it. It would be nice to not travel so much, but that's the world we live in at the moment," Penrith half Nathan Cleary said.

"It does make it a big game (on Saturday).

"But in saying that it's a big game as it is anyway.

"Any time you come up against a powerhouse team like Souths you want to play well and get the win.

"So it's obviously no different this week."

Australian Associated Press