Paterson was a key contributor on the 2011 National League West champion D-backs but struggled mightily in April last year and was demoted to Reno on April 23 with a 37.12 ERA.
"It's been a long time," Paterson said. "It just kind of came out of the blue, so it was very exciting."
Paterson pitched well this spring and was one of the final roster cuts before Opening Day. His strong showing in March likely put him back on the team's radar and made this promotion possible.
"I think really this offseason I was so locked in to that and getting back [to the Major Leagues] and kind of putting everything out of my mind that wouldn't help with that," Paterson said. "So I think that's really helped me because when I felt like I had a good spring but I didn't make the team, it didn't affect me at all. So I think that's kind of been a big steppingstone for me in, I guess, my progression to make it back to the Major Leagues."
Paterson was 2-1 with a 2.36 ERA in 24 games with Reno, and he attributed that to his ability to keep his focus and stop putting so much pressure on himself.
"Little things aren't really too concerning for me right now," he said.
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.