Despite their current form, Manchester United have found a forever place in the history books. The Red Devils are regarded as one of the most successful and revered teams in the history of club football.After being founded in 1878, the Old Trafford natives touched the sky under their legendary manager Sir Alex Ferguson's reign. Ferguson took the mantle in 1986 and remained at the helm until 2013.During his stint, the Scottish boss helped United bag 38 major trophies. His success was directly related to his tactics, experience and most importantly, signings. He built a squad that combined youngsters and the experienced.A group of lethal youngsters that went by the name "Fergies' Fledglings" remained an asset for the club for a long time. On that note, let's take a look at five youngest debutants in United's history: Source: Transfermarkt#5 Sammy McIlroy — 17 years, 3 months, 4 daysMcIlroy marked his debut against their age-old rivals Manchester CitySammy McIlroy has a place for himself in the history of the Red Devils for various reasons. To begin with, he was the iconic Sir Matt Busby's last signing. McIlroy joined United at the tender age of 17 and marked his debut on 6th November 1971.The Northern Irish player marked his debut against their age-old rivals Manchester City. However, when the whistle blew, McIlroy had all eyes on him with one goal and two assists.Michael C@abacus_20002/5 Two players won their first international cap. 17 year old Sammy McIlroy became Northern Ireland's youngest player in the modern era (a record he would hold until Norman Whiteside made his bow at the 1982 World Cup Finals)5:29 AM · Feb 16, 202152/5 Two players won their first international cap. 17 year old Sammy McIlroy became Northern Ireland's youngest player in the modern era (a record he would hold until Norman Whiteside made his bow at the 1982 World Cup Finals) https://t.co/lpVOT19O72Mcllroy left the club in 1982 to join Stoke City.#4 Ryan Giggs — 17 years, 3 months, 1 dayGiggs signed the pro-contract with united on 29th November 1990, the very day he turned 17Ryan Giggs is probably one of the top names that comes to mind when one hears "Manchester United". The Welsh international started and ended his professional career with just one club, i.e., United!Giggs signed the pro-contract with united on 29th November 1990, the very day he turned 17! The youngster was the answer to Sir Alex's left winger problems. Over the course of years, Giggs evolved into a great player, leader and a respected individual among the fans and in the dressing room.His contribution towards guiding and leading other youngsters within the club known as "Fergie's Fledglings" was massive. Giggs was the first of many United's academy players to break into the senior team.Squawka Football@SquawkaRyan Giggs' Man Utd career by numbers.Records, records everywhere! 8:47 AM · Jul 2, 2016277407Ryan Giggs' Man Utd career by numbers.Records, records everywhere! 👏👏👏 https://t.co/9pEq9UymsKHis maturity, at such a young age, benefitted the club on greater levels.