The Argentine recorded the quickest five-goal haul ever in the division as his side beat Newcastle 6-1 on Saturday. It prompted Pellegrini to again declare that the 27-year-old is the third best player on the planet.After what we have seen [on Saturday], of course Kun [Aguero] is at that level,” Pellegrini told reporters. “I have already said that, after Ronaldo and Messi, he is the best player in the world.The important thing — not only for Kun but as a team — is that we must continue to improve,” he said. “We need to win the Premier League again and to win the Champions League, because Messi and Ronaldo are always involved in that competition and that’s very important for a player.