Football managers are often perceived as older statemen ruling with an iron fist over their much younger teams, but in the modern day the times are-a-changing and there are increasingly more bosses starting out an early age.
In some cases, managers are younger than the players they give instructions to on a daily basis, but that hasn't stopped them from reaching the top level - and achieving some pretty impressive accomplishments along the way, too.
Here, FourFourTwo details the seven best managers in world football currently under the age of 40, from household names just starting out in the game to gaffers who feel like they have been around for an eternity but are still mindbogglingly young.
7. Wayne Rooney, 37 (DC United)
The miracles Rooney worked at Derby County aren't given enough credit - they were just expected of the former Manchester United and England star simply because of his name and pedigree in the game. After helping Derby survive relegation in the 2020/21 season, having taken over the side bottom of the Championship, Rooney then had to manage the club the next campaign of a shoe-string budget.
With Derby spending almost the entire season in administration, the EFL handed them with a cumulative 21-point deduction across the year. Players on short-team, price-cut deals could only be signed, with plenty of chances offered to youth team players. And yet, Rooney still nearly kept them in the Championship, eventually falling seven points short - had they not been deducted 21 points, they would have finished 17th despite the financial difficulties.
Now managing in the United States with DC United, Rooney is consistently linked with a move back to England to manage a Premier League side.
6. Will Still, 30 (Reims)
When Paris Saint-Germain turned up at the Stade Auguste Delaune - Ligue 1 side Reims' home stadium - on October 8, 2022, Reims manager Oscar Garcia was absent from the touchline, missing the clash due to family reasons. Consequently, this left then-29-year-old assistant manager Will Still in charge of the side, tasked with stopping Lionel Messi, Kylian Mbappe, Neymar and co.
He ultimately succeeded, with Reims holding the Ligue 1 juggernauts to a 0-0 draw in an ill-tempered match, in which Sergio Ramos was sent off. Just five days later, Reims had sacked Garcia and appointed Still as the caretaker manager, before eventually offering him the job on a full-time basis following an undefeated stretch of five games.
While Reims are fined €25,000 for every match Still manages, due to him not holding a UEFA Pro Licence, the French side don't seem to mind too much. And why would they when the 30-year-old managed a 14-game unbeaten streak in all competitions at the start of his full-time tenure.
5. Matthias Jaissle, 34 (Red Bull Salzburg)
A player who spent his entire career at Hoffenheim, Jaissle started coaching at Brondby as an assistant manager in 2017. After two years in Denmark, Red Bull Salzburg hired him as manager for the U18 side.
Eager for his first senior job as manager, Jaissle departed for Austrian second-tier side Liefering in January 2021. Desperate not to let a talented coach slip through the Red Bull net, Red Bull Salzburg soon offered him the chance to become the manager later that same year.
Following in the footsteps of the likes of Roger Schmidt, Adi Hutter, Marco Rose and Jesse Marsch, Jaissle is a relative unknown across Europe but, at 34-years-old, is certainly a manager to keep an eye on for the future. An Austrian Bundesliga and Cup double was secured in 2022, and it would be silly to put it past his side achieving once again in 2023.
4. Vincent Kompany, 36 (Burnley)
Upon leaving Manchester City in 2019, Kompany joined Anderlecht as player-manager. Enduring the club's worst start to a league campaign in 20 years, Kompany soon stepped down as manager to focus on being a player. When he retired at the end of the season, though, Anderlecht reinstated him as manager, and he performed much better second time around.
Fourth and third-place finishes followed in the Belgian Pro League, including a Belgian Cup final appearance. His side lost the final to Gent, though, leaving Kompany trophy less in Belgium as he headed for Burnley, following their relegation to the Championship.
Having reshaped the club since arriving, Kompany's appointment has seem an inspired one. Four Manager of the Month awards have followed for the 36-year-old, with Burnley storming to the Championship title and back to the Premier League.
3. Domenico Tedesco, 37 (Belgium)
Tedesco has graduated through the youth teams of coaching, beginning his fledgling career at Stuttgart. He soon progressed up the ranks before earning his first senior job in 2017 as the manager of 2.Bundesliga side Erzgebirge Au. After guiding them to safety, Schalke made a move for Tedesco in the summer of the same year, where he spent a season-and-a-half in charge.
Sacked after a 7-0 drubbing at the hands of Manchester City in the Champions League, Spartak Moscow were still impressed an offered him a role as manager. A fan favourite in Russia, the Covid-19 pandemic curtailed his plans at the club, but the 36-year-old wasn't out of a job for long, with RB Leipzig appointing him their new boss.
The Italian-German manager won the first trophy of his career by lifting the DFB-Pokal come the end of the 2021/22 season, with Belgium naming him as Roberto Martinez's replacement following World Cup 2022.
2. Ruben Amorim, 38 (Sporting Lisbon)
After retiring from professional football as a player in 2017, Amorim has gone from strength to strength as a manager in Portugal. He started his coaching career with third-tier Portuguese side Casa Pia ahead of the 2018/19 season, before moving to Braga's reserves in September 2019. Three months later, following the dismissal of Ricardo Sá Pinto, Amorim took over the senior side and began to flourish.
Indeed, he guided Braga to Portuguese League Cup glory that season, beating Porto in the final, before helping the side beat Benfica away for the first time in 65 years. Sporting Lisbon were alerted to his presence, and made their move for him after he had just two months of top-flight experience.
Sporting haven't looked back since, excelling with Amorim at the helm. During his first full season in charge, Amorim led Sporting to their first league title in 19 years, setting a record for the longest unbeaten streak in a single season - 32 games in a row.
1. Julian Nagelsmann, 35 (Bayern Munich)
Rising to the Bundesliga before his 30th birthday with Hoffenheim, Nagelsmann helped the German side qualify for the Champions League for the 2017/18 season. In a 3-1 defeat to Bayern Munich in January 2019, he became the youngest ever coach to manage 100 Bundesliga games.
RB Leipzig swiftly came knocking later that summer, with Nagelsmann still only 32. During his first season in charge, he helped the club reach the Champions League semi-final for the first time in its history, where they eventually lost to PSG. After just two impressive seasons at RB Leipzig, Bayern Munich were convinced and offered him their vacant managerial position.
Still only 35-years-old, Nagelsmann won the Bundesliga in his first season in charge - the first major trophy of his young - albeit fast-tracked - managerial career. He has come under scrutiny recently, but make no mistake, he is destined for greatness.