Throw into play? (4)
I believe the answer is:
cast
I believe this clue is a double definition.
'throw' is the first definition.
(I know that cast is a type of throw)
'play?' is the second definition.
(cast is a kind of play)
'into' acts as a link.
(Other definitions for cast that I've seen before include "Set of performers" , "Thrown" , "Squint to see" , "Actors; toss" , "Provided players" .)