Introduction making umpire stride around (7)
I believe the answer is:
preface
'introduction' is the definition.
(I know that preface is a type of introduction)
'umpire stride around' is the wordplay.
'umpire' becomes 'ref' (short for referee).
'stride' becomes 'pace' (synonyms).
'around' indicates putting letters inside.
'ref' inserted into 'pace' is 'PREFACE'.
'making' is the link.
(Other definitions for preface that I've seen before include "Book's introduction" , "Introductory statement at beginning of book" , "Preamble" , "Introduction (to a book)" , "Introductory text" .)