Paul McGregor says his side will be ready for a "street fight" and wants the Dragons to spoil Cronulla's season when they meet on Sunday.
The Sharks host St George Illawarra at PointsBet Stadium with their season on the line after slipping outside the top eight last weekend.
With eighth-placed Brisbane (21 points) hosting seventh-placed Penrith (22) on Friday night, Cronulla (20) will know that a win over the Dragons will see them climb back into the finals positions.
The match is also the first of three consecutive home games at Shark Park for Cronulla in the final four rounds.
As well as that, it could be the last derby match at Shark Park until 2022. Cronulla CEO Richard Munro confirmed late last month the club would proceed with the major redevelopment of their leagues club, forcing the Sharks to move their home games from Woolooware to alternate venues for the 2020 and 2021 seasons.
Cronulla plan to play the bulk of their home matches at either Netstrata Jubilee Stadium, Kogarah or WIN Stadium, Wollongong but want to take their home derby matches against the Dragons to Bankwest Stadium at Parramatta.
The Dragons, who broke a five-game losing streak against Gold Coast on Saturday, are still highly unlikely to make the finals. But a win over the Sharks would be a blow to Cronulla's own chances.
St George Illawarra coach McGregor said his side would need to stand up to the Sharks and not allow themselves to be bullied.
"Next week is a different story. We'll buckle down early in the week and come out and try and spoil a few sides to finish the year," he said.
"We've got Cronulla at Shark Park which is a local derby so they'll be coming out to bully us. So we've got to make sure we don't allow that. So we've got to be ready for a street fight there.
"The [loss] against Souths hurt. [Against Parramatta] we created things we didn't finish. There was a try in it but still we need to improve. And I thought we improved in attack [against Gold Coast] in a couple of really good areas. I know obviously the opposition haven't been playing well either.
"But defensively we've got to make sure that we have a big improvement on what we did [against the Titans]. The last two weeks prior to that was ok.
"Generally I thought our defence on the edges needs to be a lot better than what it was and we invited [Gold Coast] back into the game too many times."
Cronulla won the reverse fixture 22-9 in round 11 in Wollongong, with another win for the Sharks to see them hold onto the Monty Porter Cup until next season.
Recent honours between the clubs have been split evenly, with the Dragons and Sharks winning four games each from their last eight clashes.
