Borussia Dortmund and Barcelona are reportedly keen on the youngster and could make plays to steal him away from Old Trafford.
Dortmund snapped up Manchester City kid Jadon Sancho in the summer and Gomes is next on their radar.
And the Sun claim United fear losing the 17-year-old.
“There is chatter around the club that Dortmund are the latest side in for Gomes,” a source reportedly said.
“He is pals with Jadon Sancho and that could be something that tips the scales on whether he stays or goes.”
However Barcelona are also in the race after Gomes impressed at the Under-17 World Cup and for United’s youth team.
Gomes made his first team debut last season, becoming the youngest player to appear for United since Duncan Edwards at 16 years and 263 days.
He replaced Wayne Rooney in the 2-0 home win against Crystal Palace on the final day of the season.
Sancho moved to Dortmund to fast-track his chances of first team action but the 17-year-old has played just 16 minutes of Bundesliga football in two substitute appearances.
He came on for the final 10 minutes in the 3-1 defeat to Bayern Munich after making his debut in the 2-2 draw with Eintracht Frankfurt.