Trevor McDonald gets the ball for San Francisco in Wednesday's series finale. Neither pitcher is showing up with momentum. Gallen carries what was the worst ERA in the majors through mid-June — 6.10 — and was pulled after 4 innings against the Twins on June 22 after surrendering 9 earned runs and 12 hits. McDonald, for his part, has dropped 5 of his last 6 decisions with a 6.75 ERA in that stretch and lasted just 3 innings in his most recent start against Miami. The Giants are making this trip at 34-48, well on their way to a deadline sell-off. Buster Posey has said the front office will 'leave all options on the table,' though Logan Webb isn't going anywhere. Everything else around him is a wreck: 5 relievers on the IL, catcher Daniel Susac sidelined with a lower-back strain, and outfielder Harrison Bader having received a stem-cell injection for plantar fasciitis back in June. San Francisco did win its most recent game 5-0 over Atlanta, which stopped the immediate bleeding — but 34 wins in 82 games says everything that win didn't. The Diamondbacks aren't cruising. They dropped 2 straight to Tampa coming into this series — getting outscored 10-3 across those 2 games — and they're sitting exactly at .500 (41-41). The one thing keeping Arizona's offense afloat is Corbin Carroll, who is legitimately carrying this lineup. He hit 6 home runs in June alone (3rd most in MLB that month), is batting .283 with a .925 OPS, and set a new Diamondbacks franchise record by hitting his 53rd career triple, passing Stephen Drew. Carroll does not need a friendly matchup to hurt a team. The bigger picture for Arizona is bleak in the rotation: Corbin Burnes is on the 60-day IL after being shut down from throwing with a teres major strain, and Ryne Nelson's elbow is also finished for now. That makes Gallen's Wednesday start more than just a stat line — Arizona needs him to put together a complete outing or they're burning another chunk of their overworked bullpen before the second half even starts. For a club one game back of a wild card spot, there is no room for another early exit. For the Giants, just getting out of Phoenix healthy and heading toward the deadline is the whole job.