Inverness Caledonian Thistle FC tweeted the plea ahead of Wednesday night's away match against Dundee.
The message included the line: "We have no right to ask, but be there if you can."
It was posted just hours after ICTFC's Highland rivals Ross County beat Hamilton 3-2 in Dingwall.
If Hamilton had won, the Inverness club would have been relegated to the Championship.
County made the game free of charge to watch to home and away fans.
A Scottish Premiership football club fighting relegation has appealed to its fans to show their support at the team's latest crunch game.