That's because we struggle to find our striker at the moment, Richarlison had the same problem. I thought Son was pretty good, and Kulu was pretty much exactly what you described. I'd love for use to buy a new RW.I think our forward problems are bigger than Richarlison.
Son still looks way off. He had about 10-15 minutes where he seemed to get involved and hurt United, but then faded again. Got moved into the middle when Perisic came on and vanished so badly I actually thought he'd gone off too.
Kulu tried and tried and tried.....by repeatedly cutting in and shooting straight at the keeper.
The one time he went on the outside and used his right we scored from it.