Hagens, who had recently been promoted to Reno from Double-A Mobile, will give the D-backs an extra arm in the bullpen after the team played a doubleheader that included an 11-inning game.
"Definitely surprised," Hagens said when asked his reaction to the news of his promotion. "I wasn't sure if I was hearing right. It's starting to sink in today still that it's actually really happening."
Drafted by the D-backs in the sixth round of the 2009 First-Year Player Draft, Hagens had toiled for parts of six seasons in the Minors before getting his first shot.
"It kind of makes it all worth it," Hagens said. "All the long bus trips back to back, all the things you have to go through at the Minor League level, it makes it all worth it."
While he had to be patient for his first call to the big leagues, he did not have to wait long to make his debut. Hagens was thrown right into the fire in the ninth inning on Thursday, and he wound up being charged with the loss one inning later in a 5-4 defeat to the Marlins. The righty walked two and allowed three hits in a pair of innings, including a walk-off double in the 10th.
Hagens features a fastball, cutter, changeup and slider. In 25 games (19 starts) between Mobile and Reno, the right-hander was 8-7 with 4.12 ERA. Hagens walked 54 and fanned 62 in 115 2/3 innings.
"He's kind of a strike-thrower, he fields his position well, can handle the bat," D-backs manager Kirk Gibson said. "When we're looking at who we're going to bring up, we see who's available, when they've thrown and really their ability to throw strikes and locate, because that's what we're after. Makes it much easier to defend."
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.