One question I have is, why can't Gayle play that role Perez was last night? It certainly wasn't a midfield role, and Gayle is better at everything then Perez is.
Would allow us to hold the Ball up and have someone who's going to put away the chances.
I'm sure Rafa has some tactical reason as to why it wouldn't work, but I certainly don't see what Perez did that is beyond Gayle's game alongside Mitrovic.