Alcaraz v Zverev
My bet is on Alcaraz, Sascha doesn't look like he's ready for the semifinal of the Grand Slam just yet.
Medvedev v Rublev
This one is trickier. Rublev is in great form, Medvedev is a well-known hard court specialist and a US Open champion. Still my bet will be on Daniil in this Russian derby.
Medvedev game was kinda the same , with a quick 3-0 and really no chance for Rublev to actually play with tennis.
The match between Novak Djokovic and Shelton is actually going to be one-sided in my opinion. I know Shelton has done pretty good so far. But in this match I just cannot think he is actually going to beat Novak Djokovic. In my opinion Novak Djokovic is definitely going to the finals.
The match between Alcaraz and Medvedev is going to be a lot more interesting. The number one ranked player versus the number three. This is surly going to be a treat to watch in my opinion. It will definitely be interesting to see Alcaraz and Novak Djokovic in the finals. But for that to happen, Alcaraz will have to beat his next opponent, Medvedev.