See also: step-in
- (intransitive) To act as a replacement or substitute.
2011 December 29, Keith Jackson, “SPL: Celtic 1 Rangers 0”, Daily Record:
- McCoist unexpectedly ushered back a defender of his own with Kirk Broadfoot taking over from Steven Whittaker. There was, of course, another change, Kyle Bartley stepping in at centre-half to replace suspended Dorin Goian.
- (intransitive) To get involved; to act