Before a ball was kicked this year, plenty of pundits expected to see both these teams entrenched in the top eight after 25 rounds.
The contrast in fortunes is amazing - the Tricolours are timing their premiership run to perfection, with the year can't end soon enough for the Cowboys.
Match: Roosters v Cowboys
Round 21 -
Venue: Allianz Stadium
Key match-up: Cooper Cronk v Johnathan Thurston. The long-term representative teammates with Queensland and Australia will square off against each other for the final time, with JT to retire on September 1. Neither will give an inch, with personal pride on the line.
For the Roosters to win: Feed Latrell Mitchell the Steeden. The 21-year-old has taken his game to another level post Origin, and was virtually unstoppable against the Dragons last start, crossing for a hat-trick. It followed his round 19 double versus the Sea Eagles at Lottoland.
For the Cowboys to win: Jake Clifford to continue the impressive start to his NRL career. Highly touted by good judges, the young gun didn't overplay his hand in the thrilling win over the Knights, and couldn't learn off a better halves partner than Thurston.
Roosters Stat Attack: Hooker Jake Friend has been a machine when his team is defending, setting the standard in the competition with 821 tackles. Teammate Blake Ferguson is arguably the form winger of the NRL, with 376 runs in 199 appearances.
Cowboys Stat Attack: Paul Green's men find themselves equal with the Roosters (219) when it comes to negative play. In another statistic which typifies their year, their handling error count (80) is top three in the competition.
And another thing: Roosters fans have been plotting their revenge for almost a year. Saturday, September 23 was the date, where the Cowboys shocked the Tricolours 29-16 in the preliminary final. Surely history won't repeat?
Fullback for Roosters is number 1 James TedescoFullback for Cowboys is number 1 Te Maire Martin
Winger for Roosters is number 2 Daniel TupouWinger for Cowboys is number 2 Kyle Feldt
Centre for Roosters is number 3 Latrell MitchellCentre for Cowboys is number 3 Enari Tuala
Centre for Roosters is number 4 Joseph ManuCentre for Cowboys is number 4 Kane Linnett
Winger for Roosters is number 5 Blake FergusonWinger for Cowboys is number 5 Justin O'Neill
Five-Eighth for Roosters is number 6 Ryan MattersonFive-Eighth for Cowboys is number 6 Jake Clifford
Halfback for Roosters is number 7 Cooper CronkHalfback for Cowboys is number 7 Johnathan Thurston
Prop for Roosters is number 8 Jared Waerea-HargreavesProp for Cowboys is number 8 Matthew Scott
Hooker for Roosters is number 9 Jake FriendHooker for Cowboys is number 9 Jake Granville
Prop for Roosters is number 10 Siosiua TaukeiahoProp for Cowboys is number 10 Jordan McLean
2nd Row for Roosters is number 11 Boyd Cordner2nd Row for Cowboys is number 11 Gavin Cooper
2nd Row for Roosters is number 12 Isaac Liu2nd Row for Cowboys is number 12 Coen Hess
Lock for Roosters is number 13 Victor RadleyLock for Cowboys is number 13 Jason Taumalolo
Interchange for Roosters is number 14 Dylan NapaInterchange for Cowboys is number 14 Ben Hampton
Interchange for Roosters is number 15 Zane TetevanoInterchange for Cowboys is number 15 Shaun Fensom
Interchange for Roosters is number 16 Mitchell AubussonInterchange for Cowboys is number 16 John Asiata
Interchange for Roosters is number 20 Sean O'SullivanInterchange for Cowboys is number 17 Scott Bolton
Roosters: Sean O'Sullivan replaces Kurt Baptiste on the bench. Ryan Matterson moves to five-eighth for Luke Keary (knee) with Kurt Baptiste recalled on the bench, although halves Mitch Cornish and Sean O'Sullivan are also in the reserves. Dylan Napa (knee) returns on the bench in place of Lindsay Collins.
Cowboys: The Cowboys are 1-17. Matt Scott starts at prop with John Asiata moving to the bench.
Head-to-head: Played 36; Roosters 25 wins, Cowboys 11 wins
Previous result: Cowboys won 29-16 at Allianz Stadium in Finals Week 3, 2017
Points per game: Roosters 22.8; Cowboys 16.1
Points conceded per game: Roosters 14.8; Cowboys 21.3
Televised: Live on Nine, Fox League
Petero Civoniceva's prediction: It has to be the Roosters in this one. They're at home and they're the form team of the competition alongside the Storm. I can really see their push towards the finals picking up momentum and they're a team full of confidence at the moment and they're defending really well. It was a good bounce back by the Cowboys last week but it's been a nightmare of a season and I don't see them being in the same class as the Roosters.
Tip: Roosters by 12