Despite being yet to represent the Red Devils at senior level, the 20-year-old is rated as one of the most exciting youngsters in the Old Trafford set-up after impressing on loan at Barnsley last season.
The England U20 bagged nine goals in 27 appearances for the League One side, including the opening goal in a 3-1 Playoff Final victory over Millwall.
That prompted rumours of a permanent move to Barnsley or a shock move to United’s historic rivals Leeds United.
But according to Sky Sports, the former Bolton Wanderers academy starlet looks set to sign for West Ham instead – with a medical in East London now scheduled.
Fletcher will technically sign on a free transfer but as he’s arriving from another Premier League club and is under the age of 24, the Hammers will have to pay a compensation fee.