The England Under-15 international looks set to leave Derby this summer, with United understood to be leading the chase for his signature. Manchester City have also shown interest in the forward.
Henry became one of the youngest players ever to feature in the Under-18 Premier League this season, appearing in the competition just months after turning 14. He played 24 minutes across two matches at that level for Derby.
It was his form across the club's various youth age groups that caught the eye, with his 45-goal haul marking him out as one of the most prolific young attacking talents in the country.
Any move to Manchester United would trigger a compensation package owed to Derby, with the final figure determined by Henry's age, the length of time he has spent in the club's academy, the academy category of the signing club, and Derby's development and training costs.
The two clubs will first attempt to agree that figure between themselves, reports the Manchester Evening News. Should they fail to reach a resolution, the matter would be referred to a Professional Football Compensation Committee tribunal for a binding decision.
United have run the rule over a number of promising young players at rival academies this summer as they continue working to strengthen their pipeline of emerging talent.
The compensation system that will determine any fee owed to Derby is designed to protect smaller clubs when academy products move to bigger rivals before turning professional, recognising the investment made in a player's development even at such an early stage of his career.
Henry's rapid rise through Derby's youth ranks, culminating in senior involvement at 14, has made him one of the most closely watched prospects in English youth football this year, with his goalscoring record across multiple age groups suggesting a level of physical and technical development well ahead of his years.