Taking on competition leaders Manly at Kogarah on Monday, the Dragons are back into play-offs contention after they won four of their past five games.

Victory on Monday would not put the Dragons in the top eight after Melbourne, Wests Tigers and Brisbane won their games on the weekend.

It would, however, put them one win clear of the Cowboys and Eels, who suffered losses at the weekend, while the Titans won to keep their hopes alive.

The Dragons produced their most impressive performance of the season in their last Monday fixture - a 24-12 victory over Melbourne at WIN Stadium in round 16 - and backed it up five days later with a gritty 27-24 win over the Cowboys at Kogarah.

They face a similar task this week with Monday's match against the competition leaders to be followed by a Sunday clash with top-eight rivals Tigers in round 20, with matches against top-four sides Roosters and Panthers to follow in consecutive weeks.

Manly are in ominous form after a 40-8 demolition of the Tigers last week but Nightingale insisted the Dragons were up for the challenge after their bye.

"I think we've gathered a bit of momentum over the last few weeks and coming off the bye we should have no excuses going into our biggest game of the year against the team that's coming first," he said.

"It's a massive challenge going up against the team that's played the most consistent footy all year and that will show us where we're at but we've still got to win a lot of games after that should we win this weekend to make sure we're in the finals.

"We're still trying to make something out of this year. Our finals campaign hinges on every week.

"Every week changes our position on the ladder.

"We need to be aware of that and make sure we put in solid performances every week."

The Dragons will be without lock Trent Merrin, who suffered a shoulder injury in Origin III that's expected to keep him out until the Roosters match.

He'll be a reluctant spectator on Monday but is confident his side has what it takes to cause the upset in his absence.

"I've had a look at our run home and we've got some tough teams we're coming up against - this will really test us," Merrin said.

"We haven't played them this year and they're one of the top four teams.

"It's definitely going to be a big test but I've got all faith in the boys.

"I know they can do the job."