People need to calm down a bit about this hype – so reactionary over one good game. I can probably count the number of times Upamecano played against top teams/forwards on one hand. Koulibaly, along with Chiellini and Bonucci, have been the best centrebacks in Italy over the past five years and played at the highest level in UCL for many years.
Upamecano looks exciting but Koulibaly is complete and I can’t see him declining already. He has at least 3-4 years on top top level, perhaps even more. Upamecano could turn out a Maldini or a John Stones, either way it’s taking a chance and we need experience.