#2 Romelu Lukaku
Simply put, he is not good enough! His first touch to control the ball is atrocious, to say the least, and his ability to stay calm in pressure situations is non-existent.
Here’s a stat to ponder upon: the 2 penalties he has taken so far for United, he has put the ball between the keeper and his post at waist height without power and of course both have been saved.
His third penalty against Derby in the shootout was the exact replica of his first 2 and had the keeper done his homework, he would've saved it all day long. Lukaku missed at least 15 absolute sitters last season, many of which would have resulted in extra points, and 4 this season with little to no pressure from the defenders.
Most of his goals last season for club and country were simple tap-ins or headers from around the 6-yard box and most of them were first touch finishes and only on 7 occasions, he had to take a second touch.
Now to be fair, had he been at Liverpool, Spurs or City, he could have gotten away with the missed chances but because of United's defensive tactics, him being absolute lethal with such chances becomes extremely crucial. Agreed that Mourinho likes tall strong strikers who can outmuscle any defender – Drogba, Diego Costa, Ibrahimovic, Diego Milito come to mind.
But all these players managed to score from nothing. They had/have the ability to score a goal from absolutely nothing. Lukaku? Not so much. Whatever the stats say, simply put, he is not a United-calibre striker.