Past players rather dull? (8)
I believe the answer is:
overcast
'rather dull?' is the definition.
(as in overcast weather)
'past players' is the wordplay.
'past' becomes 'over' (both can mean finished).
'players' becomes 'cast' (group of actors).
'over'+'cast'='OVERCAST'
(Other definitions for overcast that I've seen before include "not entirely fair" , "(Of weather) cloudy, dull" , "State of a dark cloudy sky" , "Overacts, being gloomy" , "State of the sky when it is covered by clouds" .)