Newcastle's Lewis Hall (left) has been called up to the England squad for the first time
Carsley will return to his role as Under-21s manager after Nations League games against Greece and Ireland, with Thomas Tuchel starting as the new boss in January.
Hall, 20, has impressed for Newcastle this season, playing in all 10 Premier League games and could provide an answer to England's left-back problems.
Harwood-Bellis, 22, has also been an ever-present for Southampton and has impressed during a difficult start to life back in the Premier League for his club.
"They're both players who have played a lot of minutes this season and have shown they can consistently play in the Premier League at a high level," said Carsley.
Manchester City defender John Stones and Manchester United midfielder Kobbie Mainoo are ruled out with injuries, but Declan Rice, Jack Grealish and Cole Palmer are included in the 26-man squad despite fitness issues of their own.
Uncapped Liverpool midfielder Curtis Jones is also back in the squad after his maiden call-up for last month's games against Greece and Finland.
England head to the Olympic Stadium in Athens next Thursday to face Greece, who have a three-point cushion over them at the top of Group B2, before hosting Ireland three days later.
Defeat in Athens would end England's chances of automatic promotion from the second tier of the Nations League.
Tuchel has signed an 18-month deal that begins on January 1, so will only be an interested observer during this month's games.
"He hasn't had any influence on the squad selection," said Carsley. "I've spoken to him by text, but it's literally congratulations.
"I think he's highly respectful of the job that not only myself, but the staff are doing."
England squad:
Goalkeepers: Dean Henderson, Jordan Pickford, Aaron Ramsdale
Defenders: Trent Alexander-Arnold, Levi Colwill, Marc Guehi, Lewis Hall, Taylor Harwood-Bellis, Ezri Konsa, Rico Lewis, Kyle Walker
Midfielders: Jude Bellingham, Phil Foden, Conor Gallagher, Morgan Gibbs-White, Angel Gomes, Curtis Jones, Cole Palmer, Declan Rice
Forwards: Anthony Gordon, Jack Grealish, Harry Kane, Noni Madueke, Bukayo Saka, Dominic Solanke, Ollie Watkins
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)
Short link: