The 19-year-old, who played twice in the Premier League last season, embarks on his first temporary move away from United.
The Tunisian international spent pre-season with the first-team squad and featured in two games on the tour of Thailand and Australia, as well as the final friendly against Rayo Vallecano at Old Trafford.
He will now be hoping to impress and receive regular game-time with Blues, continuing his progress in a new environment whilst being closely monitored and supported by United staff.
The Academy graduate joins up with John Eustace’s side and could make his debut as early as tomorrow night, in the Championship game against Norwich City, subject to confirmation of registration by the FA and EFL.