The Red Devils will be under the temporary tutelage of the 63-year-old for the first time during Sunday's Premier League battle with Crystal Palace.
Rangnick has admitted that January transfers will be "difficult" for the club, but Haidara is thought to be one of the German's top winter targets.
Now, The Sun reports that United are preparing to trigger his £32m release clause next month as Rangnick closes in on his first Red Devils signing.
The report adds that Rangnick has "all but agreed" a deal for the 23-year-old following talks with his agent, and his participation in the Africa Cup of Nations with Mali will not present a roadblock.
Haidara boasts 10 goals and six assists from 100 games for Leipzig in all competitions, and his deal with the Bundesliga outfit is not due to expire until 2025.
body check tags ::