On the opposing side, A's infielder Ryon Healy notched his fourth homer of the spring, a solo shot against Bradley in the fourth. Bradley allowed four other hits on the day, striking out two and walking none.
A's starter Raul Alcantara, making a bid for one of two open rotation spots, allowed two runs on four hits with two walks and a strikeout in 3 1/3 innings.
"I don't know that that was his best stuff today," A's manager Bob Melvin said, "but the way it started out early on, I think he managed it fine."
Veteran reliever Santiago Casilla, making just his second appearance of the spring for Oakland, allowed a hit to his first batter, but proceeded to induce a double-play ball and strike out his final hitter for a clean seventh inning.
D-backs up next: The D-backs take a break from Cactus League competition Saturday and will play host to the Netherlands' World Baseball Classic team. Zack Greinke will start for the D-backs in the game which begins at 1:10 p.m. MST and can be seen on MLB.TV.
Athletics up next: The A's will play host to the Padres on Saturday, with expected Opening Day starter Kendall Graveman slated to take the mound in the 1:05 p.m. PT matchup at Hohokam Stadium. Right-handers Frankie Montas and Ryan Dull are also scheduled to pitch in the game.
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Jane Lee has covered the A's for MLB.com since 2010. This story was not subject to the approval of Major League Baseball or its clubs.