I hope Coutinho, Umtitti and Vidal get significant playing time, we need them to be ready for the real games. The second half will be the last chance to play for quite a while for quite a few or the squad.
I expect the rotation patterns to be quite different this season than last season. If Arthur, Vidal and Roberto don't crack the first 11, Valverde will still make sure to give them regular playing time. Those first few supersubs will soak up almost all available substitute/rotation minutes. Having subs of that quality available will reduce the overuse of several players that we saw last season.
I really hope to see a Dembele - Messi - Malcom forward line at one stage this game.
Would be a good test.
Should play the starters from the start and use the subs later. The players that arrived still need match practice whereas our subs got to play most of the pre-season games in the States.