A heartbreaking one-point defeat to South Sydney just about put paid to their finals hopes, though those willing to create A Beautiful Mind-like equations can still find a way for the Dragons to get there.

Finishing on 26 points, possibly 25, may buy a side a finals pass. That's purely the numbers game, it says nothing about the form slump that's seen the Dragons win just two of their last 12 games.

On that score they'll need a miracle more than a calculator and Vaughan said turning that around remains the immediate priority with six games to play.

"I think we just need to worry about backing that game up on the weekend where we put in the effort and we're competing," Paul Vaughan said.

"All you really ask for when you play footy is that everyone's working for each other and trying to have your mates back. That's what we want to get back to this week.

"It's good that we can compete with a top four side like that and the effort was there. We could've won that game.

"It's a bit heart-breaking when the boys put in like that and have the game stolen away at the end there but we can take some positives out of it for this week."

The performance against Souths coincided with the return of Gareth Widdop and Zac Lomax from injury, leaving stood-down lock Jack de Belin the only player unavailable for this Sunday's clash with Parramatta at Kogarah.

Vaughan said it's a boost as his side looks for a strong finish to the year.

"At video this morning [McGregor] was saying that the weekend was the first time he's had all players available that he could pick apart from Jack [de Belin]," Vaughan said.

"The squad we have on paper's pretty special so, for me, it's a little bit frustrating where we are at the moment but we just need to put a solid 80 minutes together this weekend."

The Dragons led 14-6 at halftime the last time the two sides met in round eight, only to concede 26 points in the second half in a 32-18 loss that forced them out of the top eight.

They haven't returned, with that result one of a number they've come to rue as the season reaches its pointy end. Sunday offers a shot at revenge.

"That's one that got away," Vaughan said.

"The story of the year's been we've started really well, the first 40 in games has been great and in the second half we just can't hold it.

"That's where we've lost games, in the second half. That [round eight] game is one of those games that definitely went that way but we can't look too far back.

"Parra are a dangerous side, they generate a lot of second phase so it's going to be another tough one.

"We just want to back up what we did on the weekend with that effort and just start winning some games over the back end of the year."