Webb-Foster, a first year apprentice in City's youth team, was given his maiden outing in the senior set-up when he replaced Filipe Morais in the 85th minute of the third round tie at stadiummk.
Aged 16 years and 200 days this Tuesday, Webb-Foster was only 59 days older than the youngest ever recorded player to play for the club's first team when he entered the field at MK Dons.
Robert Cullingford is currently registered as the club's youngest ever player when he featured for City against Mansfield Town in April 1970 aged only 16 years and 141 days.
Having scored 17 goals for City's youth team while still registered in the club's under 16's group last season, Webb-Foster has netted five goals in four matches for the youth team already this campaign.
Webb-Foster was joined on the bench at stadiummk by fellow scholars James King, Sam Wright and James Pollard.
Bantams boss Phil Parkinson said: "The sight of Reece (Webb-Foster) making his debut for the club will hopefully send a message out to the other players in our youth ranks that we are a club keen to progress our younger players.
"It should also show to them that there is a clear path from the youth team through into the first team here at the football club at the moment."