Not sure about this. Mane still looks rapid, his issue has been composure in front of goal mainly, he still gets loads of chances and in front of defences. Son too, very often he'll get in behind teams but then his first touch will let him down.
Kane IMO in recent games has looked better in terms of aggression/ability to beat a man. But he was awful and looked tired today. It's been an odd season though, we've already sacked a manager, we've hired a new one with a totally different system who demands a lot physically, and we don't really help out either player with service so their confidence must be shot.
You give these things more time. It's a bad season so far from both, and a REALLY bad game today. But neither are even close to the biggest problems at the club.