Neath will be outnumbered ten to one at Stradey Park, when they face Llanelli in the Principality Cup quarter-finals on Saturday (Kick-off 5.30pm).
The Welsh All Blacks have been slow in taking up tickets for the crunch West Wales clash and the crowd scenes are set to be 'all Scarlet'.
Llanelli officials are warning Neath fans in particular to book tickets in advance using the hotline number (0871 871 8088) or face being disappointed on the day.
"The ticket computer tells us Neath fans are staying away from Stradey this weekend," said commercial manager Ross Davies.
"And we only hope they don't all expect to turn up on matchday. Scarlets have been buying ten times the amount of tickets in advance and that can only mean there will be a lot of disappointed Neath fans come kick-off."
Llanelli coach Gareth Jenkins is preparing his side for a Heineken Cup quarter-final clash with Perpignan at Stradey Park the following week, but says this match stands alone in Llanelli's must win list.
"These are one off games and it's winner takes all when you get out there on the pitch," he added.
"It stands on its own as a local derby with a huge prize at stake and we have a huge opportunity to play at the top of our ability and progress in the Principality Cup.
"Neath have beaten us twice already this season and will not be coming here with anything but victory in mind.
"They don't show the same respect to home advantage that other teams do and they won't think twice about beating us in our own backyard.
"Preparation has been a challenge this week, as we have welcomed a host of players back from international duties. But those players have lead the tempo in training and we have been impressed by everyone's attention to detail."
Llanelli: Barry Davies; Garan Evans, Matthew Watkins, Leigh Davies (Captain), Salesi Finau; Stephen Jones, Dwayne Peel; Phil John, Aled Gravelle (cor.), Martyn Madden, Vernon Cooper, Chris Wyatt, Dafydd Jones, Simon Easterby, Scott Quinnell
Replacements: Iestyn Thomas, John Davies, Jamie Cudmore, Ian Boobyer, Guy Easterby, Gareth Bowen, Tal Selley
A special video package as Pontypridd claimed the double for the first time in their history by winning the Principality Premiership final, including match build-up, highlights, post match reaction and dressing room celebrations.