The 2005-born winger - who joined the AZ academy in 2006 - is yet to make his senior debut for the club, but he has been thriving at various age group levels over the past few years.
Mostly comfortable on the right flank, Addai has amassed an impressive 10 goals and four assists from 13 matches in the current campaign, becoming a regular starter for AZ's Under-21s in the Eerste Divisie.
The teenager has struck nine goals and set up two more in 12 second-tier matches this term, sitting joint-second in the Golden Boot race with Cambuur's Milan Smit and only one behind current leader Martijn Kaars of Helmond Sport.
Addai also dazzled for AZ's Under-19s in a recent UEFA Youth League win over Molde, scoring one goal and providing two assists in a thrilling 4-3 success during the first leg of their second-round tie.
The winger would have done his prospects of a marquee European move no harm with that display on November 7, as according to FootballTransfers, Man United had scouts in attendance to watch him.
The Red Devils are not expected to be the only team vying for Addai's signature, though, and the 18-year-old - who has not represented the Netherlands at any international level yet - is under contract with AZ until 2025.
The Dutch side are therefore not in a position to demand an astronomical fee for their highly-rated starlet, who penned his current terms upon his promotion to the Under-21 squad last summer.
Man United's wide options have flattered to deceive this season, with Marcus Rashford, Alejandro Garnacho, Antony, Mason Mount, Jadon Sancho and Facundo Pellistri managing just one Premier League goal between them.
Antony's season has also been disrupted by allegations of domestic violence from a former partner and one other woman, although he denies the claims and has continued to represent Man United amid the ongoing investigations.
However, Sancho has now been frozen out of the squad for over two months due to his public spat with Erik ten Hag, whom he effectively accused of lying about his omission from September's loss to Arsenal.
After Ten Hag put Sancho's absence down to mediocre displays in training, the England winger hit back at his head coach on social media, claiming that he had been made a "scapegoat".
Given his refusal to apologise to Ten Hag, Sancho has been banished from the first-team facilities at Man United's Carrington training complex and is expected to leave either in January or next summer.
Furthemore, Mason Greenwood - who is still contracted to Man United for another two years - has no future at the club after the Red Devils performed a U-turn on their decision to re-integrate him into the squad.
Greenwood has been rebuilding his career with Getafe since all criminal charges against the attacker were dropped earlier this year, and the Spanish side are apparently keen to sign him on a permanent basis.