In Cup red player, yard away, smashed upright (13)
I believe the answer is:
'upright' is the definition.
'in cup red player yard away smashed' is the wordplay.
'yard' becomes 'y' (abbreviation).
'away' suggests deleting specific letters.
'smashed' indicates an anagram.
'incupredplayer' with 'y' taken away is 'incupredplaer'.
'incupredplaer' anagrammed gives 'PERPENDICULAR'.
(Other definitions for perpendicular that I've seen before include "Gothic style following 7" , "At right angles" , "Style of late English Gothic church architecture" , "Like this answer [1A], relative to 1 dn" , "Sort of architecture" .)