Manchester City have signed an absolute gem in Erling Braut Haaland.

The Premier League champions are acquiring the world-class striker for around €60 million after activating his release clause at Borussia Dortmund.

For a 21-year-old who's already among the best footballers on the planet, that fee looks a mere pittance in the modern market.

Haaland has scored goals for fun during the course of his young career and is only going to get better.

But how does the Norwegian compare to other great players from this century when they were aged 21 or under?

Well, we have some answers.

Using Transfermarkt, we've worked out the 25 most prolific seasons (goals and assists combined for a team in one of Europe's top five leagues) by a footballer in the aforementioned age bracket since the turn of the millennium.

Erling Haaland celebrates at Borussia Dortmund
DORTMUND, GERMANY - MAY 22: Erling Haaland of Borussia Dortmund celebrates after scoring their team's first goal during the Bundesliga match between Borussia Dortmund and Bayer 04 Leverkusen at Signal Iduna Park on May 22, 2021 in Dortmund, Germany. Sporting stadiums around Germany remain under strict restrictions due to the Coronavirus Pandemic as Government social distancing laws prohibit fans inside venues resulting in games being played behind closed doors. (Photo by Matthias Hangst/Getty I

DORTMUND, GERMANY - MAY 22: Erling Haaland of Borussia Dortmund celebrates after scoring their team's first goal during the Bundesliga match between Borussia Dortmund and Bayer 04 Leverkusen at Signal Iduna Park on May 22, 2021 in Dortmund, Germany. Sporting stadiums around Germany remain under strict restrictions due to the Coronavirus Pandemic as Government social distancing laws prohibit fans inside venues resulting in games being played behind closed doors. (Photo by Matthias Hangst/Getty Images)

And Haaland occupies two spots in the top five...

The 25 best seasons by an U21 player in the 21st century

=25. Mario Gotze (Borussia Dortmund, 2012/13) - 36

Goals: 16 | Assists: 20

=23. Sergio Aguero (Atletico Madrid, 2008/09) - 36

Goals: 21 | Assists: 15

=23. Kylian Mbappe (AS Monaco, 2017/18) - 36

Goals: 21 | Assists: 15

22. Gonzalo Higuain (Real Madrid, 2008/09) - 36

Goals: 24 | Assists: 12

21. Mauro Icardi (Inter Milan, 2014/15) - 36

Goals: 27 | Assists: 9

Mauro Icardi during his Inter Milan days
MILAN, ITALY - DECEMBER 20: Mauro Emanuel Icardi of FC Internazionale Milano scores his goal during the Serie A match between FC Internazionale Milano and SS Lazio at Stadio Giuseppe Meazza on December 20, 2015 in Milan, Italy. (Photo by Marco Luzzani/Getty Images)

MILAN, ITALY - DECEMBER 20: Mauro Emanuel Icardi of FC Internazionale Milano scores his goal during the Serie A match between FC Internazionale Milano and SS Lazio at Stadio Giuseppe Meazza on December 20, 2015 in Milan, Italy. (Photo by Marco Luzzani/Getty Images)

20. Sergio Aguero (Atletico Madrid, 2007/08) - 36

Goals: 26 | Assists: 10

19. Eden Hazard (Chelsea, 2012/13) - 37

Goals: 13 | Assists: 24

18. Gonzalo Higuain (Real Madrid, 2009/10) - 37

Goals: 29 | Assists: 8

17. Harry Kane (Tottenham Hotspur, 2014/15) - 37

Goals: 31 | Assists: 6

16. Thomas Muller (Bayern Munich, 2010/11) - 38

Goals: 19 | Assists: 19

Thomas Muller in action for Bayern vs Inter
MILAN, ITALY - FEBRUARY 23: Lucio of Inter Milan tussles for posession with Thomas Muller of FC Bayern Muenchen during the UEFA Champions League round of 16 first leg match between Inter Milan v FC Bayern Muenchen on February 23, 2011 in Milan, Italy. (Photo by Valerio Pennicino/Getty Images)

MILAN, ITALY - FEBRUARY 23: Lucio of Inter Milan tussles for posession with Thomas Muller of FC Bayern Muenchen during the UEFA Champions League round of 16 first leg match between Inter Milan v FC Bayern Muenchen on February 23, 2011 in Milan, Italy. (Photo by Valerio Pennicino/Getty Images)

15. Roberto Firmino (Hoffenheim, 2013/14) - 38

Goals: 22 | Assists: 16

14. Wayne Rooney (Manchester United, 2006/07) - 38

Goals: 23 | Assists: 15

=12. Mesut Ozil (Werder Bremen, 2009/10) - 39

Goals: 10 | Assists: 29

=12. Mesut Ozil (Real Madrid, 2010/11) - 39

Goals: 10 | Assists: 29

11. Jadon Sancho (Borussia Dortmund, 2019/20) - 40

Goals: 20 | Assists: 20

Jadon Sancho with Borussia Dortmund vs Spurs
DORTMUND, GERMANY - MARCH 05: Jadon Sancho of Borussia Dortmund in action during the UEFA Champions League Round of 16 Second Leg match between Borussia Dortmund and Tottenham Hotspur at Westfalen Stadium on March 05, 2019 in Dortmund, North Rhine-Westphalia. (Photo by Dean Mouhtaropoulos/Getty Images)

DORTMUND, GERMANY - MARCH 05: Jadon Sancho of Borussia Dortmund in action during the UEFA Champions League Round of 16 Second Leg match between Borussia Dortmund and Tottenham Hotspur at Westfalen Stadium on March 05, 2019 in Dortmund, North Rhine-Westphalia. (Photo by Dean Mouhtaropoulos/Getty Images)

10. Kylian Mbappe (AS Monaco, 2016/17) - 40

Goals: 26 | Assists: 14

9. Karim Benzema (Lyon, 2007/08) - 41

Goals: 31 | Assists: 10

8. Eden Hazard (Lille, 2011/12) - 44

Goals: 22 | Assists: 22

7. Cristiano Ronaldo (Manchester United, 2006/07) - 45

Goals: 23 | Assists: 22

6. Kylian Mbappe (Paris Saint-Germain, 2019/20) - 48

Goals: 30 | Assists: 18

Kylian Mbappe celebrates a goal for PSG
MANCHESTER, ENGLAND - FEBRUARY 12: Kylian Mbappe of PSG celebrates after scoring his sides second goal during the UEFA Champions League Round of 16 First Leg match between Manchester United and Paris Saint-Germain at Old Trafford on February 12, 2019 in Manchester, England. (Photo by Michael Regan/Getty Images)

MANCHESTER, ENGLAND - FEBRUARY 12: Kylian Mbappe of PSG celebrates after scoring his sides second goal during the UEFA Champions League Round of 16 First Leg match between Manchester United and Paris Saint-Germain at Old Trafford on February 12, 2019 in Manchester, England. (Photo by Michael Regan/Getty Images)

5. Erling Haaland (Borussia Dortmund, 2020/21) - 53

Goals: 41 | Assists: 12

4. Kylian Mbappe (Paris Saint-Germain, 2020/21) - 53

Goals: 42 | Assists: 11

3. Erling Haaland (Borussia Dortmund, 2019/20) - 54

Goals: 44 | Assists: 10

2. Kylian Mbappe (Paris Saint-Germain, 2018/19) - 56

Goals: 39 | Assists: 17

  1. Lionel Messi (Barcelona, 2008/09) - 57

Goals: 38 | Assists: 19

Lionel Messi celebrates a goal for Barcelona vs Bayern
BARCELONA, SPAIN - APRIL 08: Lionel Messi of Barcelona celebrates his goal during the UEFA Champions League quarter final first leg match between FC Barcelona and FC Bayern Munich at the Camp Nou stadium on April 8, 2009 in Barcelona, Spain. (Photo by Jamie McDonald/Getty Images)

BARCELONA, SPAIN - APRIL 08: Lionel Messi of Barcelona celebrates his goal during the UEFA Champions League quarter final first leg match between FC Barcelona and FC Bayern Munich at the Camp Nou stadium on April 8, 2009 in Barcelona, Spain. (Photo by Jamie McDonald/Getty Images)

Some legendary names feature and as per usual, Messi sits at the top of the pile.

Mbappe features an astonishing five times, which is utterly absurd when you think about it.

The Frenchman and Haaland certainly are the future of football and it'll be a huge shock if one of them doesn't go on to win the Ballon d'Or.

To be honest, they're both likely to scoop the accolade at some point...

Premier League quiz: 20 questions on the division's all-time records