Member of the team keeps tardy worker on track (10)
I believe the answer is:
platelayer
'worker on track' is the definition.
'platelayer' can be an answer for 'worker' (platelayer is a kind of worker). I'm unsure of the 'on track' bit.
'member of the team keeps tardy' is the wordplay.
'member of the team' becomes 'player' (I can't justify this - if you can you should give a lot more credence to this answer).
'keeps' indicates putting letters inside (inserted letters are kept inside).
'tardy' becomes 'late' (synonyms).
'player' placed around 'late' is 'PLATELAYER'.
Can you help me to learn more?
(Other definitions for platelayer that I've seen before include "Worker on railway track" , "Track repairer" , "He works on track" , "he's working on lines" , "one delivering good lines?" .)