The 20-year-old right back started in the Milan youth system at the age of 10 in 2002 and made his first team debut in 2011, eventually becoming a key player who has tasted Champions League action and been called up by Italy.
Academy graduates are a valuable asset to clubs with Milan's head of youth scouting, Mauro Bianchessi, estimating in an interview with Reuters that the academy pays for itself if every three years a player is brought into the first team.
As the economic climate bites, Milan want to do better than that and their objective is to get one player each season from the Primavera (oldest youth team age group ranging from 15 to 20) into the first team.
"To give you a example, De Sciglio now isn't worth anything less than 10 million euros ($12.96 million), and Alberto Paloschi, another Milan product, was recently part-sold to Chievo (Verona) for around 4 million euros," Bianchessi said.
"Next year Bryan Cristante, who is the youngest Milan player to ever debut in the Champions League (third youngest overall), will be in the first team squad at 17 years old. He is an asset and as such is worth money to the club."
Milan's academy has 10 categories which begins with training for children as young as 8 years old and finishes with the Primavera.
The club tries to help them get used to a potential future life as a footballer by taking them to tournaments around Europe to play against the continent's other top sides.
"The development of a player can't only be sporting, but also cultural," Bianchessi said.
"We want to develop footballers, obviously, as that's our job, but we also want to develop them into men with a certain cultural outlook."
There is also an emphasis on a scientific approach to players' physical development, involving the club's MilanLab research centre.
Over the last six years MilanLab has measured players' performances for a variety of physical activities, and grouped the results into player position, actual age and biological age.
The biological age is taken from ultrasound analysis of players' bone structure and varies widely among adolescent boys.
"That way we can see how players are performing against those at a similar level of physical development, as well as allowing us to compare performance with players from the first team for each position," MilanLab physical trainer Domenico Gualtieri said.
"If the club has a player that it considers talented but is physically behind, we look to spend a bit more of our resources on their training."
The desire for more academy successes comes amid sobering statistics that show that even reaching the first team is still no guarantee of huge dividends for the club.
Of the 21 academy players to make first-team debuts since the 2009-10 season, nine have played for Milan in the league or Europe, although only two of those more than once - De Sciglio and Alexander Merkel, who signed for Udinese in January.
Ten of them are currently on loan with Serie B (second tier) and Lega Pro (third and fourth tier) clubs.
It does not mean they will not make it with Milan but it shows that cases like that of De Sciglio are rare.
"Everyone has their own path at the end of the day, you have to give them time, and there isn't one single path to first team football that works for everyone," Filippo Galli, head of the youth set-up and who played for Milan from 1983 to 1996, said.
"For one player it might be best to let them go and play for a year in the Lega Pro, while for another it's better that they stay here and train with the first team, even if they're not going to play.
"However at a club like Milan, where the targets and ambitions are very high, it is very rare that a player comes straight up from the youth team to the first team. De Sciglio is the exception that proves the rule." ($1 = 0.7717 euros)