Reports say the Ligue 1 strugglers value Fofana, who has a contract at the club until summer 2015, at £5 million.
And a swoop for a burgeoning right-sided defender is needed, given that United's only actual established right-back is Rafael da Silva.
Fofana could be the best choice, given that he's already starting to break into the Nice team and will develop good experience in one of the best top-flight leagues in Europe.
He made his debut for Ligue 1's basement team recently in their 1-0 defeat to high-flyers Montpellier and gave a steady performance beyond his years.
He didn't have too many touches of the ball, but was reliable when called upon.
A player with excellent ability in the tackle, Fofana is both robust and accurate, something of a dying art amongst full-backs.
He's also very good at clearing the danger, with all three of his clearances against Montpellier effective.
The Nice academy graduate also has a good eye for a pass and is more accurate than most his age with a long ball, while he's also quite a quick player who can keep up with tricky wingers.
And what makes him so good for Manchester United is that he has the physique to be a success in the Premier League, as well as the technical ability and forward-thinking mindset to play the United way.
Of course he needs to bulk up a bit given that he's only young and needs to develop his reading of the game better, but that should come with further game time at Nice.
Overall, Diacko Fofana is a player with big potential as proven in the youth ranks and at £5 million could represent a sound investment.
He's quite over-priced at the moment—especially given that full-backs often go for less money as they're less likely to influence a game—but if United snap him up soon, that fee could become a bargain.