The young Magpies were due to face Man City's second-string on Sunday, 18th October at Whitley Park, with kick-off set at 4pm (BST).
However, the league match will now take place on Monday, 12th April 2027 at the same venue, with the kick-off time moving to 7pm (BST).
Robbie Stockdale's side resume their Premier League 2 campaign on Monday, 26th October when hosting local rivals Sunderland at Whitley Park (kick-off 7pm GMT).
Any further fixture amendments for Newcastle United Under-21s will be confirmed on **newcastleunited.com** at the earliest opportunity.