Sir Alex often got confirmation of PL players he was interested based on how they performed against us. We saw this with Saha, Rio, Ashley Young, Zaha and many others. Whenever a player played against us and performed he was sure he was after the right man. He even did this with Ronaldo after a pre-season friendly
Other than Lukaku's hattrick against us in SAF's last game which was a dead rubber tbf, Lukaku was trash in every game against us. He has been completely nullified by Bailly, Rojo, Blind and Paddy fecking McNair. I could be wrong but I don't think he scored against us playing for Everton.
Everything about his career so far, tells me he's not cut out for the big stage.