Schlupp has been on trial at United since January but Sir Alex Ferguson has still to decide whether to sign him from the Foxes.
Reports surfaced earlier this week United were close to signing the 20-year-old Ghana international, who is primarily an attacker but can also play at left-back, but a deal is yet to be agreed.
Although he completed the full 90 minutes at Upton Park, Schlupp was unable to steer United to victory in a goalless draw.
Schlupp, who has made eight Championship appearances for Leicester this season, also featured for United's U21s against Liverpool on Monday.
The Ghanaian, who is contracted at Leicester until 2015, came through the Foxes' academy and was handed his first-team debut by former boss Sven Goran Eriksson.