Crossword Genius

Sportsman's warning over athlete's predecessor (10)

Ross

I believe the answer is:

forerunner

I'm a little stuck... Click here to teach me more about this clue!

'predecessor' is the definition.
(I know that predecessor can be written as forerunner)

'sportsman's warning over athlete's' is the wordplay.
'sportsman's warning' becomes 'fore' (I can't justify this - if you can you should give a lot more credence to this answer).
'over' means one lot of letters go next to another (in a down clue, some letters go over others).
'athlete' becomes 'runner' (type of athlete).
'fore'+'runner'='FORERUNNER'

Can you help me to learn more?

(Other definitions for forerunner that I've seen before include "Precursor" , "one coming ahead" .)

I've seen this clue in The Telegraph.
Want a hint initially instead of a full solution? Install my app