Flanagan has also confirmed prop Hame Sele is only likely to return from a heart issue this season if the Dragons make a deep run into the post-season.
Flanagan's first year at the helm is shaping as the Dragons' best since 2018, despite the squad being dismissed as wooden spoon candidates in the pre-season.
The Saints sit in eighth place on the ladder with two games to play in the regular season, daring to dream of a first finals berth in six years.
"We've got to get there, that's the challenge now, is win two football games and we'll give them a pass mark (for the season)," Flanagan said.
"Then it's a new competition and we'll throw everything at it if we can get there."
The Dragons' poor for-and-against and a gap of only two points between the chasing pack means they can ill-afford a repeat of last week's big loss to Cronulla across the next fortnight.
Lose to the 16th-placed Eels and the Dragons could find themselves as low as 11th on the ladder to finish the round, their hopes of returning to the top eight dependent on other sides losing.
But beat Parramatta and Canberra and the Dragons cannot be ousted.
Flanagan added "you could probably say" Saturday's match at CommBank Stadium was his side's most important of the season yet.
"We need to win and the following week, we need to win as well. If we don't win tomorrow, (finals) definitely is out of our hands," he said.
"It's definitely a big one.
"You don't want to be sitting there worrying about other team's results."
Raymond Faitala-Mariner is back for the trip to Parramatta, with Moses Suli a chance to make a late charge into the 17 on return from a knee injury. Sele's outlook is less rosy.
The prop has not played since being taken to hospital with chest pains during the round-23 loss to Canterbury.
He was later diagnosed with pericarditis, a condition that causes inflammation of the tissue around the heart.
Flanagan had been hopeful after last week's loss Sele could return to face Parramatta but revealed on Friday the Dragons might not have him back this year.
"I'd like to say we would but it's slowly, slowly with Hame," he said.
"It's not something you can play around with, the ticker. He's just got to slowly introduce himself back into training.
"Maybe if we went deep into the semi-finals you could see him but I wouldn't think you'd see him, definitely not this week, and more than likely not next week, either."
Flanagan shrugged at reports linking the Dragons with out-of-favour Eels prop Reagan Campbell-Gillard, whom the Saints face this weekend.
"I've just got to worry about the 17 players in the dressing room, I'm not too much worried about the opposition or next year," Flanagan said.
