I don't rate Nelson at all initially. When everyone is fawning over him and compares him to Sancho after a u23 game against City, I watched him for the first team when he broke through and he was average. And average throughout, scared of taking his man on, constantly passing back etc.
But this season I think something has changed for him, he is brave on the ball and started to play with his shackles off to become more useful. Just more impressive generally in all his appearances for us. Obviously Martinelli is a level above in talent but Nelson is easily better than Willian. Him not playing this match has nothing to do with his supposed quality, especially when our manager plays Mustafi over Saliba.