Parramatta's clash with Sydney Roosters on Thursday night headlines the run to the finals, with those two teams and Manly battling for fourth spot.

Melbourne and Penrith look set to finish in the top two, while South Sydney are likely to finish third unless one of the two sides above them stumbles dramatically.

But fourth spot remains vital, with no team having come from outside the four to win the premiership in the NRL era.

Heading into Thursday's clash, Parramatta (28) sit two points clear of the Roosters (26), while Manly are one win further back on 24.

But the Eels have the hardest run home of all teams, with games against the rest of the top five.

The injury-ravaged Roosters' draw is also challenging with clashes against the Eels, Panthers and Rabbitohs, while Manly have Parramatta and Melbourne on the run home.

"We've put ourselves in the position and it's up to us now to finish in the top four," Eels coach Brad Arthur said.

"It would be nice to finish in the top four.

"There won't be a home ground advantage if we stay in Queensland but you at least get two cracks.

"But we've got a lot of work to do between now and then. We can't be really concerned about that.

"Except that whatever we get come finals time will be on the back of what we do now. It's all in our own hands."

The "reward" for whoever finishes fourth would be a date with the eventual minor premiers to start the finals.

However, it would result in a second chance with a loss, while an upset win would catapult them into a preliminary final.

Meanwhile, the Roosters need to overturn their recent run against the top sides to topple Parramatta, having not beaten one of the top-six since their wretched injury run began in late March.

"There is opportunity when it comes to ladder and position," coach Trent Robinson said.

"But all that matters for us is Thursday.

"If you watch the game you would understand we're looking for continuity in how we want to play. The rewards will come if we play well enough"

NRL'S TOP-FOUR RACE AND KEY GAMES

4. Parramatta - 28 points

5. Sydney Roosters - 26 points

6. Manly - 24 points

ROUND 20

Roosters v Eels

ROUND 21

Eels v Rabbitohs

Roosters v Panthers

Sea Eagles v Storm

ROUND 22

Sea Eagles v Eels

ROUND 24

Roosters v Rabbitohs

Storm v Eels

ROUND 25

Eels v Panthers.

Australian Associated Press