Manager Derek Adams made ten changes to his team - though it be came nine when Caolan Lavery was injured in the warm-up - and saw his back-up players beaten by the most promising young Red Devils not out on loan or in the squad for Wednesday's League Cup tie.
The 3-0 defeat did not look on the cards after a controlled first-half performance, except for the fact the a Bantams side who have not scored enough goals lately created very little. Whatever else their opponents lacked, they came with a guarantee of quality which meant they were always likely to score at some point.
Charlie Savage - son of Robbie - put them in front shortly after half-time with the aid of a deflection off captain-for-the-night Yann Sanogo'o and from that point there was an air of inevitability about what followed.
Joe Hugill tapped in a second, Dillon Hoogewerf added a third and striker Andy Cook' s night off was cancelled with around half an hour to play.
Playing a 4-1-4-1 formation with Sanogo'o as the holding midfielder, a much-changed Bantams did a good job of controlling the first half, forcing Manchester United Under-21s to drop Shola Shoretire back from a two-boy attack into a five-boy midfield.
The visitors were not quite as billed, as shown when the 35-year-old ginger head of Paul McShane headed away Kian Scales's early free-kick. The former Hull City defender and Barnsley loanee joined as a player-coach this summer.
Levi Sutton and Gareth Evans - who, as the only player retained from the weekend in the team originally picked must have wondered what he had done wrong - combined well on the left, the latter's dinked ball early on cut out by Teden Mengi before the former could run onto it.
Sutton picked up the second ball when McShane headed away, but Ollie Crankshaw's pass back to him was distinctly unsympathetic.
City chose to be without a specialist centre-forward when Lavery withdrew in the warm-up and when his stand-in Alex Gilliead robbed Alvaro Fernandes, Scales shot at Czech Under-21 international Matej Kovar.
It was low-octane stuff, with plenty heading for the concourses ten minutes before the interval to beat the... err... rush?
Sam Hornby made a comfortable save from Shoretire - the only player bar McShane with Premier League experience - at an early corner and Sanogo's stepped in to stop a flowing move coming to anything.
Hornby could at least say he saved from Zidane, denying Zidane Iqbal as the game picked up towards the interval. Shortire beat him from a move started by Iqbal's sweeping pass but was rightly flagged offside.
Crankshaw's cross-shot forced a save at the other end and he caused McShane enough trouble to get the veteran booked for pulling him down.
Adams had brought Threlkeld on in midfield and Charles Vernam on the wing, putting Scales at centre-forward to try to change the game but not the way things quickly panned out as an unconvincing Hornby punch presented Savage with a chance at the start of the second half.
Matty Foulds was caught in possession by half-time substitute Hoogewerf, who drilled the ball over for Hugill to convert.
Bradford's lack of confidence in front of goal was becoming painfully obvious. Earlier in the half Sutton had finally got a shot away after the crowd virtually begged him, and when the recently-introduced Cook got on the end of a cross his downward header could not trouble Kovar.
When he got in behind Teden Mengi, he delayed ong enough for the centre-back who was on loan at Derby County last season to get back and tackle him and no one ran one to his wonderful curling cross a minute later. Crankshaw volleyed the last kick of the match into the net, but from an offside positon.
Hoogewerf jumped on a slip by Sanogo'o - by now at centre-back - and went down the middle to add a third after 83 minutes, sliding on his knees in front of the 230 away fans in a 2,022 crowd but the game had long since been lost.
Bradford City: Hornby; Cousin-Dawson, Sikora (Cook 64), Staunton, Foulds; Songo’o; Crankshaw, Evans, Sutton (Threlkeld 46); Scales, Gilliead (Vernam 46).
Unused substitutes: O’Donnell, Kelleher, Watt.
Manchester United Under-21s: Kovar; Fernandez, Mengi, McShane, Hardley (Hoogewerf 46); Wellens, Svidersky, Savage, Iqbal (Garnacho 86); Shoretire, Hugill (Emeran 81).
Unused substitutes: Mee, Jurado, Mainoo, Murray.
Referee: A Backhouse (Carlisle).