The Arizona Diamondbacks host the Athletics at Chase Field on Tuesday, July 21, 2026, with first pitch scheduled for 9:40 PM ET. Arizona sends right-hander Kohl Drake to the mound against Oakland's Jack Perkins in what shapes up as a pitching matchup between two arms with something to prove. With the dog days of summer in full swing, every game in this stretch carries weight for a Diamondbacks club looking to position itself for the playoff race.

Probable Pitchers: Kohl Drake vs. Jack Perkins

Kohl Drake draws the start for Arizona. The young arm has been working to carve out a consistent role in this rotation, and a home start at Chase Field gives him a familiar environment to build on. Detailed ERA and record figures are not available heading into this one, so how he manages the strike zone and sequences his pitches early will be the first thing to watch.

Jack Perkins takes the ball for Oakland. Like Drake, Perkins is a pitcher worth monitoring as both clubs evaluate what they have heading into the second half. Neither starter comes in with a well-publicized track record at the major league level, which makes this a genuine proving-ground start for both men.

Arizona Diamondbacks Starting Lineup

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

Keys to Watch at Chase Field

Ketel Marte Leading Off

Marte sliding into the leadoff spot at DH is the lineup's most important variable. He sets the table for everything that follows, and how he works Perkins in his first at-bat will signal the tone for the entire offense. When Marte is locked in, this lineup has legitimate length from top to bottom.

Corbin Carroll in the Three Hole

Carroll batting third puts him in position to do damage with runners on base from Marte and Perdomo. Carroll's combination of speed and bat-to-ball ability makes him a constant threat, and he is exactly the kind of hitter who can turn a modest inning into a crooked number against a starter still establishing himself at this level.

Nolan Arenado's Impact in the Middle of the Order

Arenado at third base and batting sixth gives the Diamondbacks a professional presence in the heart of the lineup. His defensive reliability at the hot corner alone changes games, and if the lineup turns over, he becomes a high-leverage out for Perkins to navigate.

Drake's Command Against an Oakland Lineup

With limited statistical context available on Drake, command will be the storyline. If he throws strikes early and keeps the Athletics off the bases, Arizona's offense has enough firepower to give him a lead to work with.

Prediction

The Diamondbacks hold the home advantage at Chase Field and carry a lineup with genuine proven pieces in Marte, Carroll, and Arenado. Arizona wins this one, 5-3, with Drake delivering a serviceable five-plus innings and the offense doing enough damage early against Perkins to make it hold up.