Plays safe in t-shirts, to some extent (6)
I believe the answer is:
feints
'plays' is the definition.
(I've seen this before)
'safe in t-shirts to some extent' is the wordplay.
'to some extent' indicates a hidden word.
'FEINTS' is hidden in the letters of 'safe in t shirts'.
(Other definitions for feints that I've seen before include "Deceptive actions" , "Deceptive manoeuvres" , "Makes slight attack to divert attention as in fencing" , "Deceptive or pretended blows" , "Mock attacks, in fencing say" .)