Cronulla captain Paul Gallen says there is a "false sense of security" top four sides get by having a second chance, something the Sharks can't worry about.
Sea Eagles held strong with limited possession to come out winners and send out coach Geoff Toovey a winner, while Sharks will look to bounce back in finals.
After losing the chance to finish fourth on the ladder, Cronulla Sharks coach Shane Flanagan said it's now of a matter of moving onward to the NRL Finals.
Manly have upset the finals-bound Sharks 14-12 in a thriller, denying Cronulla a place in the top four on the NRL Telstra Premiership ladder.
Jack Bird still remembers the advice given to him by Josh Dugan when they were teammates at the Dragons. He hopes to use it during the finals.
Cronulla can sew up fourth spot on the NRL ladder with a win over Manly on Sunday, booking a date with the Sydney Roosters in the qualifying final.
The Sharks are looking to cement a place in the top 4, while the Sea Eagles will need a miracle to make their 11th consecutive finals appearance.
If Cronulla fullback Michael Gordon got his way back in May, he would be playing his final game of the season this weekend against the Raiders in Eels colours.
Sharks coach Shane Flanagan says his side has been guilty of looking too far ahead towards the finals rather than the games directly in front of them.
A thrilling and topsy-turvy game was finally won by Cronulla, who stole it back late after it looked like the Eels had come from behind for an unlikely win.