England cricketer batting — good, getting established (7)
I believe the answer is:
rooting
'getting established' is the definition.
(establishing with roots)
'england cricketer batting good' is the wordplay.
'england cricketer' becomes 'Root' (Joe Root plays cricket for England).
'batting' becomes 'in' (as in batting or being 'in' in cricket).
'good' becomes 'g' (abbreviation).
'root'+'in'+'g'='ROOTING'
(Other definitions for rooting that I've seen before include "Implanting deeply" , "Rummaging" .)