Sign made by team leader at sporting event (5)
I believe the answer is:
trace
'sign' is the definition.
(thesaurus)
'team leader at sporting event' is the wordplay.
'leader' says to take the initial letters.
'at' is a charade indicator (letters next to each other).
'sporting event' becomes 'race' ().
The first letter of 'team' is 't'.
't'+'race'='TRACE'
'made by' is the link.
(Other definitions for trace that I've seen before include "Find - tiny portion" , "Detect - a small amount" , "Make a copy using transparent paper" , "Find; copy; small amount" , "Element" .)