Very keen on Prague centre's own goal (4)
I believe the answer is:
agog
'very keen' is the definition.
'agog' can be an answer for 'keen' (I've seen this before). I'm not sure about the 'very' bit.
'on prague centre's own goal' is the wordplay.
'on' means one lot of letters go next to another.
'centre's' says to take the centre (I've seen 'centred' mean this).
'own goal' becomes 'OG' (football abbreviation).
The middle of 'prague' is 'ag'.
'ag'+'og' is 'AGOG'.
Can you help me to learn more?
(Other definitions for agog that I've seen before include "Open-mouthed" , "All ears" , "Impatient" , "Enthralled" , "Bug-eyed" .)