But that wasn't a concern this early in spring training for the right-hander, who is expected to be the Diamondbacks' No. 2 starter.
He allowed seven runs and six hits in 2 1/3 innings. He gave up a solo home run to Jay Bruce, walked two, struck out none and threw a wild pitch during a blustery afternoon at Tucson Electric Park. The wind at game time was 19 mph.
"Probably rushing a little bit. I didn't really have a feel for any pitch. That's never a good thing when you never establish a feel for any pitch," said Jackson, who is 0-1 with an 8.59 ERA. "Couple balls up. They put them in play."
Asked if it was a concern, Jackson smiled.
"If it was a concern for me right now, we'd have big problems," he said. "If one outing was a concern, (manager) A.J. (Hinch) would need to pull me into his office and have a nice little talk with me."
"I've had plenty outings where you come in and it wasn't what you wanted to do," he added. "All you can do is go back and analyze the situation and go from there."
He said he was still able to get his work in. And he is healthy.
Hinch said Jackson, who joined the Diamondbacks in December from the Detroit Tigers, just had an off day.
"It looked like he had a hard time gripping the ball," Hinch said.
"Everything from the get-go, he was fast with his delivery, had a lot of velocity coming out, but his command was off. He was a little jumpy off the rubber."
For the Reds, starter Johnny Cueto allowed two runs in 3 2/3 innings. He struck out one and walked one.
Drew Stubbs entered the game hitting 2 for 20, but went 2 for 3 with a double and triple and two RBIs to improve his average to .174.
"Just putting together quality at-bats," he said. "It's all I'm concerned about."
Bruce went 2 for 3 with two RBIs and his second homer of the spring. He is batting .391.
It was the Reds' first trip to Tucson since the team moved to its spring complex in Goodyear. The Reds will also travel to Tucson on March 25 to play the Colorado Rockies.
Notes: Reds third base prospect Juan Francisco made his first start in left field and didn't have a putout. He went 1 for 3 with an RBI single. ... Diamondbacks third baseman Mark Reynolds, who has agreed to a three-year, $14.5 million deal, had the day off after playing four consecutive days and didn't come to the ballpark, Hinch said. The manager said he will be giving his other every day position players days off.