Rested, having marked out playing field earlier (8)
I believe the answer is:
reclined
'rested' is the definition.
(I've seen this in another clue)
'marked out playing field earlier' is the wordplay.
'marked out' becomes 'lined' (I can't explain this - if you can you should give a lot more credence to this answer).
'playing field' becomes 'rec' (recreation ground).
'earlier' means one lot of letters go next to another.
'lined' put after 'rec' is 'RECLINED'.
'having' acts as a link.
Can you help me to learn more?
(Other definitions for reclined that I've seen before include "Leant back comfortably" , "Leaned in a resting position" .)