Knuckle curveball a key pitch for D-Backs prospect Archie Bradley

Diamondbacks starting pitcher prospect Archie Bradley is hoping his knuckle curveball will be a pitch that carries him onto the major-league roster in 2015, per MLB.com.

"For a knuckle curve, you're not throwing it like a normal curveball where you're snapping your arm," Bradley said. "I was able to throw it at a young age, and it's just something that has been successful for me in pro ball.

"It's a pretty unique pitch. When I'm throwing it well, it has some pretty hard 12-to-six break. Sometimes I'll get on the side with it and make it go a little sideways, but for the most part, I just try to keep it the same and just keep going."

Diamondbacks manager Chip Hale has been impressed with Bradley a few days into camp. Bradley is considered a top 100 prospect by Baseball America (No. 25) and MLB.com (No. 15).

"The workouts and everything that he has done so far have been fantastic," Hale said. "He's been very professional about his work and his bullpens are getting better and better."