The Arizona Diamondbacks head to Busch Stadium on Tuesday, June 23, for a 7:45 PM ET first pitch against the St. Louis Cardinals. Eduardo Rodriguez gets the ball for Arizona, squaring off against Cardinals right-hander Kyle Leahy in what shapes up as an intriguing pitching matchup between a veteran arm trying to find his rhythm and a young Cardinals starter looking to prove he belongs. Road wins in St. Louis are never easy, and this one carries real weight as the D-backs chase ground in the NL standings.

Arizona Diamondbacks at St. Louis Cardinals: Tuesday, June 23, 2026

Eduardo Rodriguez takes the mound for Arizona in a role that has been equal parts promising and frustrating this season. The left-hander has the stuff to dominate on any given night — sharp changeup, deceptive delivery — but consistency has been the question mark hanging over every one of his starts. Busch Stadium is a legitimate road challenge, with its intimate dimensions and a Cardinals crowd that gets loud in a hurry. Rodriguez will need to attack the strike zone early and avoid deep counts against a St. Louis lineup that is more than capable of grinding at-bats.

Cardinals Starter Kyle Leahy: A Tough Read for Arizona's Lineup

On the other side, Kyle Leahy is a name the D-backs' coaching staff will have spent time breaking down this week. Young Cardinals starters can be unpredictable — sometimes that inexperience works against them, but sometimes a pitcher with fresh looks and a chip on his shoulder will give a veteran lineup fits. Arizona's hitters need to be disciplined early, work counts, and not let Leahy get comfortable by attacking chase pitches out of the zone.

Keys to Watch for the Diamondbacks

• Rodriguez's command in early innings: If he can get through the first two frames without crooked numbers, Arizona's offense has enough firepower to stay competitive deep into the game.
• Handling the Cardinals' middle of the order: Jordan Walker and Nelson Velázquez give St. Louis legitimate run-producing threats. Rodriguez must be careful when traffic builds on the bases.
• Arizona's lineup vs. a fresh arm: The D-backs will face Leahy without a large sample of recent data. Patience and pitch recognition will be critical, especially early in the game before the book opens up on him.
• Bullpen depth: With a road game and uncertainty around pitch counts, Arizona's relievers may be called on earlier than ideal. How the pen responds will go a long way toward determining the outcome.

Cardinals Lineup to Watch

St. Louis will send out a lineup headlined by Jordan Walker in the cleanup spot and Masyn Winn, one of the more dynamic young shortstops in the National League, batting sixth. JJ Wetherholt leads off at second base, while Iván Herrera slots in as the DH. Lars Nootbaar and Blaze Jordan round out the bottom of the order — this Cardinals lineup doesn't have many easy outs.

Prediction: A Tight Game That Comes Down to Late Innings

This one has all the makings of a low-scoring, competitive ballgame. If Rodriguez is on — and when he's on, he's genuinely difficult — Arizona can steal a road win on Tuesday night. But Busch Stadium is a tough environment, and the Cardinals are playing good baseball at home. Expect a 4-3 game that goes to the seventh or eighth before a decision is made. Arizona ekes this one out, 4-3, with Rodriguez going six solid and the bullpen closing the door. Tune in on Arizona Sports 98.7 FM or DBACKS.TV.