Study Pietersen's opening in cricket? (7)
I believe the answer is:
inspect
'study' is the definition.
(I know this)
'pietersen's opening in cricket?' is the wordplay.
'opening' says to take the initial letters.
'in' indicates putting letters inside.
'cricket?' becomes 'insect' (cricket is a kind of insect).
The first letter of 'pietersen' is 'p'.
'p' going inside 'insect' is 'INSPECT'.
(Other definitions for inspect that I've seen before include "Study" , "Go over" , "Scan" , "Check" , "vet" .)