The 19-year-old, who joined the Magpies from West Ham United in the summer of 2018, enjoyed a fine month, starting all three of United's Premier League 2 division two fixtures as well as the 2-1 Leasing.com Trophy defeat at Macclesfield Town.
He also scored a stunning goal in a 3-2 win over Norwich City and his displays have earned him a place on an eight-man shortlist - chosen by the Premier League Football Development panel after club coaches nominated the best performances by opposing players in each league fixture - for the award.
Nominated alongside Longelo - who will be looking to continue his good form as United's second-string take on their Hull City counterparts in the Premier League Cup on Friday evening - are Folarin Balogun of Arsenal, Everton's Anthony Evans, George Hirst of Leicester City, Manchester United's James Garner, Michael Olise of Reading, Southampton's Callum Slattery and Anthony Scully of West Ham United.
The winner, also chosen by the Premier League Football Development panel, will be announced on Friday, 11th October. August's winner was Chelsea's Billy Gilmour.