When Lionel Messi made his Barcelona debut at the age of 16 years and four months old, no one knew how the footballing world was about to change.
A bushy-haired diminutive Argentine, the attacker replaced Portuguese star Deco, earning his first substitute appearance against none other than Jose Mourinho's Porto.
His first action? To get the ball on his left foot and cut inside with rapid acceleration and close touch control.
That was a piece of play was to quickly become his trademark, eventually earning his La Liga debut in the 2004/05 season. His first goal was assisted by Ronaldinho in a strike that summed both Messi and the Brazilian up in a nutshell.
Ronaldinho dinked the ball over the Albacete defence and then with the confidence of someone who's been at the top level for years, Messi chipped it over the goalkeeper.
It was a landmark moment as Albacete goalkeeper Raul Valbuena became the first unfortunate victim of the magician's remarkable finishing ability.
Messi has since gone onto play 734 times for Barcelona, scoring 635 goals in the process.
However, who was the coach who managed to extract the most from the 33-year-old? You'd think it was Pep Guardiola, but we've gone and ranked how he fared under each head coach by his goal contributions per game.
Check out how he got on below...
8. Frank Rijkaard (2004-2008)
110 games, 42 goals, 26 assists
68 overall goal contributions
Per game: 0.61
The man to give Messi his Barcelona debut, the Argentine's stats are obviously the lowest under Frank Rijkaard. He'd only just burst onto the scene but that being said, his tally per game is quite incredible. No wonder he's gone onto do great things.
Messi, however, credits Rijkaard enormously for his career: "I think the most important in my career was Rijkaard. If he hadn't trusted in me and not decided to put me in the first team first to train and then play my first match, maybe I wouldn't have made it to the first team."
7. Ronald Koeman (2020 onwards)
3 games, 1 goal, 2 assists
3 overall goal contributions
Per game: 1
The partnership that we thought would never happen. This summer Messi expressed his desire to leave Barcelona behind in dramatic fashion. Manchester City were thought to be favourites to land the attacking dynamo but he eventually decided to stay at Camp Nou. Messi only has one goal in three games but he's still started off well under Koeman.
6. Gerardo Martino (2013/14)
46 games, 41 goals, 15 assists
56 overall goal contributions
Per game: 1.21
Martino's spell at Barcelona was trophyless and it's hardly a surprise that he ranks at number six when it comes to extracting the most from Messi. He still racked up a ridiculous 41 goals in 46 games but it wasn't enough to win them a domestic or European trophy. Martino has since managed Messi at international level with Argentina.
5. Ernesto Valverde (2017-2020)
124 games, 112 goals, 47 assists
159 overall goal contributions
Per game: 1.28
Barcelona manager until the start of this year, Valverde got an enormous amount of quality out of Messi but has to settle for fifth place on this list. The forward's tally of 1.28 goal contributions per game is absurd as Messi won two La Liga titles under the Spanish coach. Not bad at all.
4. Quique Setien (2020)
24 games, 15 goals, 18 assists
33 overall goal contributions
Per game: 1.37
The 62-year-old's reign at Barcelona ended in absolute disaster as the Spanish outfit were slapped 8-2 in the Champions League by Bayern Munich. That being said, he got plenty out of Messi, particularly when it came to chance creation. It's rare to see it, but under Setien, Messi actually made more goals for his teammates than he scored.
3. Pep Guardiola (2008-2012)
219 games, 211 goals, 91 assists
302 overall goal contributions
Per game: 1.37
In terms of goal contributions per game, the great Pep Guardiola managed to extract exactly the same out of Messi as Setien. That's pretty remarkable when you consider what happened during each of their tenures. We've put Guardiola over Setien for simple reasons - it was one of the most devasting managerial and player partnerships we've ever seen. Messi won three La Liga titles, two Champions League trophies, two Club World Cups and two Copa Del Reys.
Astonishing stuff.
2. Luis Enrique (2014-2017)
158 games, 153 goals, 73 assists
226 overall goal contributions
Per game: 1.43
Are you kidding me? 226 goal contributions in 158 games is just daft. Messi's record under current Spain boss Enrique is freakishly good and it's hardly a surprise to see that Barcelona won a bucket load of honours under his stewardship. Two La Liga wins, three Copa Del Reys and one Champions League trophy was achieved with Enrique at the helm.
1. Tito Vilanova (2012-13)
35 games, 42 goals, 12 assists
54 overall goal contributions
Per game: 1.54
Forget Guardiola, what Vilanova managed to extract out of Messi was outstanding. Messi scored more goals than he played games and managed a ratio of 1.54 involvements per match. Tito's spell at Camp Nou was cut short by an illness that sadly took his life, but in his only season with Barca, he steered them to the La Liga title.
So there we have it. It's a shock to see that Guardiola doesn't top this list, but in terms of overall performances, there is probably no manager in Barcelona history that had more of an influence on his career.
Rijkaard may have been the one to give Messi his debut but it was Pep that made not only the Argentine one of the best ever, but also made his Barca team one of the greatest on the planet at the time.