Monk perhaps runs into trouble (7)
I believe the answer is:
brother
'monk perhaps' is the definition.
'runs into trouble' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'into' means one lot of letters goes inside another.
'trouble' becomes 'bother' ('bother' can be a synonym of 'trouble').
'r' placed into 'bother' is 'BROTHER'.
(Other definitions for brother that I've seen before include "Union member - male relative" , "Eg, monk, friar" , "Fellow-member" , "Close relative" , "Relation" .)