I don't live in some fantasy world where you can make 11 changes and play 3 academy products and win a European match.
Our squad is strong enough to support decent rotation - 6/7 at a time but not complete change of XI.
Especially when you factor in new players still to settle.
Is Bale ready to start considering how off the pace he looked?
You could start Vinicius but he's an unknown quantity and if he's having a poor game we will have to turn to Kane anyway.
The way I see it there's a certain level of quality that has to be on the pitch at all times if we want to avoid the turgid displays we've seen with the likes of Winks/Sissoko/Dele/Lucas as our options.
Having one of Lo Celso/Ndombele on the pitch at all times is imperative.
Having a proper striker is equally so. Vinicius will hopefully take this burden off Kane but I think Mourinho will be looking for a strong start and that's why I can see Kane in the XI.
Lay down a marker, bring Vinicius on for his first minutes when the game is won without the pressure to really deliver and build him up to a start from there.
For contrast I would start like this against Burnley:
Lloris
Doherty Toby Rodon Reguilon
Hojberg Sissoko
Ndombele
Bergjwin Kane Son
Of that XI only Doherty and Toby would be playing the full 90 against LASK. (Aurier could actually come on for Doherty given the 5 subs rule if we wanted to preserve him).
Ndombele would have played 45 mins and Kane 60 or so (maybe less if we have a great 1st half.
That is plenty of rotation.