The 17-year-old has made six Championship appearances for Wigan this season and scored against Hull City during the 2-2 draw in the middle of September.
On Saturday, it was revealed that the youngster had signed a new contract at the DW Stadium amid interest from the likes of Manchester City, Chelsea, Everton and Tottenham Hotspur.
However, according to the Daily Star, both United and Liverpool are still interested in bringing the striker to the Premier League despite Wigan seemingly doing enough to secure his short-term future.
The report claims that Wigan would be looking for around £5m for the academy product, although the club could demand various add-ons based on future success.
Gelhardt, who recently captained England's Under-18 side, has one goal in eight first-team appearances for his current club. body check tags ::