Letter said to offer little support (3)
I believe the answer is:
tee
'little support' is the definition.
'letter said' is the wordplay.
'letter' becomes 't'.
'said' shows a homophone (sound like).
't' sounds like 'TEE'.
'to offer' acts as a link.
(Other definitions for tee that I've seen before include "Golfer drives from it" , "Golfing item" , "Golfer's support" , "A golfer hits from here" , "Mark" .)