Both rotations are held together with duct tape right now. The Dodgers are still waiting on Blake Snell, Tyler Glasnow, Gavin Stone and Bobby Miller to work their way back from the IL, which is a big part of why a $300 million-plus roster is running out arms nobody's heard of some nights. Arizona isn't much healthier — Zac Gallen, Corbin Burnes and Ryne Nelson are all out — but their offense has stayed productive enough to keep them in wild-card position, and Pfaadt's emergence as a legitimate mid-rotation stopper has covered for a lot of that pitching attrition.
This is exactly the kind of series that decides whether a slump becomes a crisis. The Dodgers have dropped series to Boston and now been swept — well, they've lost the first 3 of the set — against the Cubs, and a National League powerhouse can't keep bleeding games against teams they're supposed to beat. Arizona, on the other hand, split its last 4 with San Diego and knows every August game carries playoff weight. Whoever looks hungrier out of the gate probably sets the tone for the weekend.
Ohtani's bat has kept L.A. competitive even as the losses piled up, and if he gets going against a D-backs bullpen that's had to soak up extra innings with the rotation banged up, this could tip back toward the Dodgers in a hurry. But until L.A. actually wins one, the pressure sits squarely on the visitors.