The 16-year-old attacker became the first ace to play in the Premier League after being born in the 21st century.
McGuinness coached teams in the academy for 23 years and helped megastars such as Marcus Rashford and Paul Pogba reach the first-team.
And the former Crewe-player reckons Gomes can make the grade despite his diminutive height.
“He’s a real talent,” McGuinness told Sky Sports . If he was Brazilian, people would be raving about him and, if he was six inches taller, people would be going mad.
“I suppose that’s our country. People doubt players if they’re short in stature but no-one is doubting Andres Iniesta or David Silva. He’s got the potential to be that type of player and, in England, you just don’t get many players like that.
“If you play him with better players, he’ll get better himself and create chances for them. You don’t want to build him up too soon but I’m sure they’ll handle all that at United.”