The Diamondbacks named Gallen as their starter for Opening Day against the Dodgers on March 26.
Merrill Kelly had previously been tapped to start Opening Day for Arizona, but he will not be ready at that point as he recovers from a back injury. As a result, Gallen -- who re-signed with the Diamondbacks at the start of spring training -- will be making his fourth consecutive Opening Day start. Gallen had a disappointing 2025 campaign, finishing with a 4.83 ERA and 175:66 K:BB over 192 innings.