In 57 appearances combined with Double-A Chattanooga and Louisville, Roenicke was 6-2 with a 2.80 ERA with 26 walks, 71 strikeouts and 13 saves.
A right-hander possessing a 98-mph fastball that makes him the organization's hardest thrower, Roenicke impressed during Spring Training.
"He wasn't scared, No. 1," Reds manager Dusty Baker said. "Him being the son of a former Major League player, he's probably not intimidated about being in the big leagues. He grew up in this setting. He was a football player, so you know he's tougher than most. And he has a good fastball. It will take you a long ways."
Despite his solid first big league camp, Roenicke was sent back to Double-A out of Spring Training with instructions to work on throwing his offspeed pitches for strikes. He also has a curveball and changeup in his repertoire.
With Chattanooga, Roenicke had a 3.27 ERA while hitters batted .253 against him. Once promoted to Louisville, he had a 2.54 ERA and the opposition average dipped to .234.
"I knew I had to focus," Roenicke said. "There were a lot better hitters and veterans up there in Triple-A. Things started clicking a lot more up there. I was more successful there than Double-A. My Dad would tell me that a lot of hitters are at Triple-A because they can't hit offspeed or breaking balls. They're all fastball hitters. My fastball is my go-to pitch, so I need to throw offspeed for strikes to show them, and then it makes my fastball more effective."
A good showing this month could put Roenicke into better position to compete for a set-up role in next year's bullpen.
Among rookies, Roenicke is older than most at 26. That's partially because his pitching career didn't really get going until his senior season at UCLA. Before that, he played football, and was quarterback as a freshman before converting to wide receiver for two years.
After the third year, Roenicke concentrated solely on baseball but split time as an outfielder and a closer. The Reds made him a 10th-round pick in the 2006 First-Year Player Draft.
"I always tell people, my age doesn't say young, but my arm is still young and I feel young," Roenicke said. "That's all that matters, I guess."