The Scottish Sun says the 15-year-old striker impressed on a first trial with the Red Devils in March.
United have made it clear they would like him to return after the coronavirus lockdown has lifted.
But it's thought they now face competition from Celtic, as well as Premier League rivals Wolves.
Isle of Lewis-born Graham – who also spent time at Liverpool's youth academy in October – only joined the Staggies last year.
But he has earned rave reviews playing for their Under-16s and 18s sides.