Other than what's already been mentioned, I can say that he's probably been the best defender in Serie A this season. He was showing potential last season with Genoa, but this season, he's showing what he's all about with Atalanta. I'm surprised that he's not getting more coverage because I can't think of another defender who's been as good as him this season.
He's been the leader of the Atalanta's back 3 at the age of 23. Despite playing beside two not so good defenders, he's been able to hold his own against the various attacking threats that he's had to face. He reads the game very well, puts in strong yet well-timed tackles frequently, and is a very difficult player to get past. His positioning's probably the best out of all defenders in the Serie A, and that's among the likes of Koulibaly, Romagnoli, de Ligt, Chiellini, de Vrij, etc. With someone of his ilk, one would think that he's probably not as physically gifted as some of the other defenders, but that's not the case here. He may not be very tall (1.85m), but he's quick and surprisingly strong, which explains why he's so tough to get past.
His only weakness, and this is a slight one, is that he occasionally tends to get drawn towards the ball, but that only happens when he's dealing with multiple threats by himself. Instead of containing all of the other threats, he sometimes chooses to go in to win the ball out of his faith in his recovery powers and quickness. Keep in mind that he does play in a back 3 in Serie A, and defenders there tend to trust their teammates more than defenders in other leagues. Currently, as Atalanta play a back 4 against Benevento (who are capable of scoring multiple goals), Romero's holding his own, so it's not like he's only good in a back 3 (he also played in a back 4 with Genoa on several occasions).
