clutch problem...

[Fazerider]

Hopefully it does only need adjusting, but if the cable went slack suddenly it may be the gizmo inside that converts a pull on the cable to a push on the clutch rod is collapsing.
The bearings can get rusty which is more likely if the rubber cap isn't there to keep rain and road salt at bay.
To investigate, you'll need to take the cover off and undo the two screws holding the mechanism on. This isn't easy as they're tight and the heads are about as hard as ripe brie.