Soldiers can make sport out of love! (6)
I believe the answer is:
troops
'soldiers' is the definition.
(I've seen this before)
'make sport out of love' is the wordplay.
'make' indicates an anagram.
'out of' is an insertion indicator.
'love' becomes 'o' (In tennis, 'love' means 'zero').
'sport' anagrammed gives 'trops'.
'trops' placed around 'o' is 'TROOPS'.
'can' acts as a link.
(Other definitions for troops that I've seen before include "Army" , "Military divisions" , "men" , "Groups of soldiers" , "Cavalry" .)