The Arizona Diamondbacks welcome the St. Louis Cardinals to Chase Field on Saturday, July 18, for a 4:10 p.m. ET first pitch. Brandon Pfaadt gets the ball for Arizona against Cardinals right-hander Dustin May in what shapes up as a compelling pitching matchup in the heart of the summer schedule. With both clubs looking to gain ground in their respective races, this one carries real weight beyond a single box score.

Probable Pitchers: Pfaadt vs. May

Brandon Pfaadt has been one of the more intriguing young arms in the National League since emerging as a rotation fixture for Arizona. He has the stuff to keep a Cardinals lineup honest — above-average fastball life and a breaking ball that plays up in a loud ballpark environment like Chase Field. His command will be the number to watch; when Pfaadt is dotting his spots, he gives the D-backs every reason to feel good about their chances.

Dustin May brings a lively sinker to the desert, and St. Louis will lean on him to generate early contact and keep Arizona's lineup off balance. May has durability questions in his career history, but when he is on, he can be a genuine handful for right-handed bats in particular. Arizona's lineup construction will matter here.

Arizona Diamondbacks Starting Lineup

• 1. Ketel Marte — 2B
• 2. Geraldo Perdomo — SS
• 3. Corbin Carroll — RF
• 4. Gabriel Moreno — DH
• 5. Max Kepler — LF
• 6. Nolan Arenado — 3B
• 7. Tim Tawa — 1B
• 8. James McCann — C
• 9. Ryan Waldschmidt — CF

Keys to Watch

Ketel Marte Setting the Table

Marte leading off is a luxury not every team has. His ability to work counts and get on base in front of Perdomo and Carroll gives Arizona a dangerous top-of-the-order combination that can manufacture runs without waiting for the long ball. If Marte is seeing the ball well early, the Cardinals bullpen could be tested sooner than St. Louis would like.

Corbin Carroll as the Middle-of-the-Order Catalyst

Batting third, Carroll is the engine. His speed alone changes how St. Louis has to defend him, and with Moreno hitting cleanup behind him, pitchers cannot afford to let Carroll get comfortable. Watch for stolen base attempts and pressure on May to work quickly.

Arenado Back at Chase Field

Nolan Arenado batting sixth for the Diamondbacks against his former organization is one of the more compelling storylines in this lineup. Whether that surfaces in motivation or production, it adds a layer worth tracking through his at-bats against Cardinals pitching.

Pfaadt's Command in the Early Innings

The Cardinals will look to make Pfaadt work hard early. If he can get through the first two innings without putting baserunners on via walks, Arizona's defense should be able to handle the rest. Chase Field plays big, and a locked-in Pfaadt can exploit that.

Prediction

Arizona takes this one. Pfaadt handles a Cardinals lineup that has to adjust to the desert heat, the Chase Field dimensions, and a D-backs defense that is built to play behind a pitch-to-contact starter. Look for the D-backs to do damage early against May and let Pfaadt work into the sixth. Diamondbacks 5, Cardinals 3.