Extras, perhaps, in theatrical sequences (4)
I believe the answer is:
runs
This clue is a double definition.
'extras perhaps' is the first definition.
(extra is a type of run in cricket)
'theatrical sequences' is the second definition.
(run can mean a series of theatrical performances)
'in' acts as a link.
(Other definitions for runs that I've seen before include "Moves fast" , "ladders" , "Jogs" , "Points scored in cricket" , "Manages" .)