Both Champions League matches hinge on the first forward pass. Shakhtar and Sporting can each turn a midfield recovery into a wide box entry, while Galatasaray and Stuttgart have more than one route to a final touch. The key in each game is whether the receiving midfielders can keep supplying the box after the first exchange.
Shakhtar's Isaque and Ocheretko must get the ball beyond Sporting's first press to Alisson, whose right-side finishes against Obolon followed another live contribution against Dynamo. Sporting's Fresneda has supplied Pedro Lima and Suárez, but Shakhtar's Riznyk has already made important saves against Inter. Pedrinho left the Inter game injured and Isaque has since played the replacement role. I expect Shakhtar's midfield retention and Alisson's box arrival to keep the home side in the contest, so I'm siding with Shakhtar.
Galatasaray can feed Osimhen through Torreira and Sara, as its recent home box volume shows. Stuttgart have already found another route without Stiller: Karazor and Prömel played the full Leverkusen match, with Undav, El Khannouss and Demirovic completing separate attacking moves. I expect that observed replacement supply to produce a response even when Galatasaray get Osimhen involved. That's why I'm siding with Stuttgart.