DORTMIND, Germany — At just 21, Kylian Mbappe is already a World Cup winner while at only 19, Erling Braut Haaland has emerged as a rising fast-star this season. As Cristiano Ronaldo and Lionel Messi approach the end of their careers, could Mbappe and Haaland be the next duo to dominate football? AFP Sport looks at the star forwards who meet when Haaland"s Borussia Dortmund host Mbappe"s Paris Saint-Germain in Tuesday"s Champions League last 16, first leg, tie. Erling Braut Haaland Haaland had barely arrived last month in Dortmund when the records started tumbling. He justified the 20 million euros ($22 million) Dortmund paid Salzburg by becoming the first player to score a hat-trick on his Bundesliga debut. Having scored 28 goals in 22 games for Salzburg, including eight in this season"s Champions League group stage, Haaland picked up in Germany where he left off in Austria. He made his debut coming off the bench with his new team 3-1 down at Augsburg in mid January. His clinical finishing produced three goals in 20 minutes to seal a 5-3 victory. The teenager was praised by Dortmund"s sporting director Michael Zorc, yet calmly replied: "You signed me to score goals". Another two followed in a 5-1 rout of Cologne, then Haaland grabbed two more goals when Union Berlin were crushed 5-0. He claimed his eighth goal in four games in Dortmund"s German Cup defeat at Werder Bremen. The Norwegian teen netted again in Friday"s 4-0 thumping of Eintracht Frankfurt to extend his own record to nine goals in six games for Dortmund. His attitude also impresses his new team-mates. "When a young player has been so hyped, with everyone saying how good he is, then he can be a difficult person," said goalkeeper Roman Buerki. "But he is a really cool guy, very professional. "I"m one of the first at training - but he"s always there earlier." Haaland sees Mbappe as a role model. "When I was in Salzburg, I started scoring goals, but I look at Kylian Mbappe banging in Ligue 1 goals, so you can always reach a higher level," Haaland told Bundesliga.com. For a player who turned 21 in December, Mbappe"s achievement"s are astonishing. The World Cup winner is also France"s reigning player of the year and has won three Ligue 1 titles with two different clubs. Mbappe recently reached a century of club goals, and his 19 in the Champions League is a record for a player before his 21st birthday. The second youngest player to score in a World Cup final after Pele, Mbappe hit double figures for Champions League goals before he had even turned 19. By that time he had already become the second most expensive player in football history when PSG signed him from Monaco for a total reported fee of 180 million euros ($215 million). Mbappe has been to Dortmund"s Signal Iduna Park before. He scored twice when Monaco drew 3-3 there in the 2017 Champions League quarterfinals, a match postponed by 24 hours after a bomb attack on the Dortmund team bus. He scored another in the return leg as Monaco advanced to the last four. At that time, he was the teenage sensation. Now, he is a World Cup winner and is PSG"s top scorer this season with 24 goals. Maybe he is beginning to develop a star"s ego. He showed his dismay at coach Thomas Tuchel when substituted in a recent 5-0 win over Montpellier. "If a player goes off and is angry with the coach, it"s a fault on his part," said PSG sporting director Leonardo, also a World Cup winner as a player. "But to then say he is a spoilt child, I don"t accept that, because he is an adorable person, very committed too, a fantastic player." However, after three successive years of failing to win a Champions League knockout tie, PSG want a return on their investment in Neymar and Mbappe where it matters — in Europe.