Defender Blumberg, 19, is a graduate of the Nike Academy and signed his first professional contract at the League One club last year. He has been a regular in Charlton’s under-23 team and played the full 90 minutes in the 3-0 defeat against the Dons in the first-round tie.
The former Hakoah Sydney City East centre-back spent almost a year training and playing at the Nike academy at St George’s Park after being selected as the only Australian out of 600 players at the Nike Most Wanted Trials in 2016.
He was offered a contract after being recognised for his leadership skills, dedication to his game and individual quality.
“My dream is definitely to play Premier League,” commented Blumberg.
Nick Blackman has joined Spanish second-tier side Sporting Gijon on a season-long loan deal from Derby County.
Blackman, 28, featured in two of Derby’s pre-season friendlies but does not feature in the plans of recently appointed manager Frank Lampard.
The striker has not played a competitive game for Derby since May 2017 and spent last season on loan at Maccabi Tel Aviv.
Blackman is a former pupil of King David High School in Manchester, and cost Derby £2.5m in January 2016 but he has scored only once in 29 appearances since his move to Pride Park.