Plymouth Albion chairman of rugby Graham Dawe says the club's fans have to back his side in Saturday's derby with Cornish Pirates.
Attendances at the Brickfields have been down this season and Dawe says that could threaten the team's professional status.
"Without people coming to watch we won't have a professional team here," he told BBC Radio Devon.
"We don't want to go back to the days when we were playing level four rugby."
"It's great to see this level of sport played in this city and long may that continue," Dawe added.
Winger Tyson Lewis will make his full debut for Albion while forwards Dan Collier and Dave Morton have recovered from injury.
"All Plymouth-Penzance games should be treated as special occasions and a one-off," Dawe said.
"We're really hoping that we're going to be competitive and win the game."