He ain't coming to Utd to be 3rd / 4th choice CB. He will be a starter alongside Martinez for most games. He's 24 and won the league in Holland, won the league in Italy and won the league in Germany. He is known for his strength, leadership, aggressiveness, tackling and aerial ability. He would be huge coup for us.
Winning titles in multiple countries by 24 isn't an easy feat. Yes he's had injuries, so has Martinez. This is where Yoro hopefully comes in and gets game time of one of them is injured.