The 20-year-old enjoyed a recent trial with the Premier League leaders, which has tempted manager Sir Alex Ferguson to pursue a permanent move.
During his spell with the Red Devils, Schlupp made an outing for the Reserves, impressing United’s backroom staff with his physicality and technique.
The Ghanaian forward has made just over 20 appearances for Leicester and spent some time on loan with Brentford in 2011.
The Foxes are unlikely to stand in Schlupp’s way should United up their interest, and would be happy to receive a respectable fee for his signature.
As well as impressing at club level, the burly front-man also received a shock international call-up, making his debut against Gabon in 2011.
Even though he has been capped by Ghana, he has also represented Germany, his birth nation, at U-19 level.
Fergie is said to be keen to draft in attacking reinforcements, with the club likely to allow multiple fringe players to leave at the end of the season.
As well as Schlupp, they have been linked with Borussia Dortmund star Robert Lewandowski, who is believed to be keen to make a move this summer.