Rugby player is upright (4)
I believe the answer is:
prop
I believe this is a double definition.
'rugby player' is the first definition.
(I've seen this in other clues)
'is upright' is the second definition.
(thesaurus)
(Other definitions for prop that I've seen before include "Support - item on stage" , "Stay" , "Lean" , "Moveable object used on stage" , "needed at certain stages" .)