I'm ok with starting with Sanchez. It's not that I want to start him but I'm more worried about overplaying Thuram/Lautaro. At some point, they do need to rest and if I had to pick a game, it'd be this one even though I think Thuram would do really well against a team like Salzburg, who I guess will play a high-line. I guess there is the argument that Sanchez may theoretically fit better playing against Roma who will be more defensive, but not sure I see him starting that game, and Lautaro/Thuram shouldn't play 3 games in a week as we need to keep them fresh.
Carlos Augusto and Frattesi need to start also imo. I was hoping for Asllani to start as well as Calhanoglu needs a rest at some point, but I guess it may end up being too much rotation at some point.