"When you think about stuff on the mound, that's a red light. That means stop," he said. "You can't pitch with a red light in your head."
Throughout the early part of the season, the former first-round pick failed to find the green light he was looking for. That is, until Tuesday.
The 21-year-old right-hander gave up two hits and struck out seven over seven innings to lead the Brevard County Manatees to a 5-0 victory over the Fort Myers Miracle.
"I felt good," Jeffress said. "I got enough sleep last night and I just came out firing."
He figured out how to control his fastball and mixed in a deceptive curve. If he ran into a red light, he simply stepped off the mound and took a deep breath before getting back to work.
"I would just think about the good things and what pitch I wanted to throw and my mechanics," he said.
Jeffress opened the season at Double-A Huntsville and went 1-3 with a 7.57 ERA in eight starts. He had 34 strikeouts over 27 1/3 innings, but he also walked 33.
He couldn't shake the red lights.
In his first two starts with the Manatees, walks continued to haunt him. But against the Miracle, he didn't walk a batter.
"Just take it one pitch at a time, one inning at a time and just go out there and play your game because, at the end of the day, it's all on you," he said.
Jeffress retired the first five batters before Deibinson Romero singled to center field. He also allowed a base hit in the fourth inning, but he was throwing strikes, so he kept the red lights at bay.
"The players here are fundamentally sound," Jeffress said. "The coaches here are awesome. There are a lot of great people around who make me feel comfortable. That's always a big key."
Not only was this performance good for his confidence, it also served as a sign he is putting his past behind him. Late in the 2007 season, the Virginia native was suspended 50 games for violating the Minor League substance abuse policy. The suspension carried over to the early portion of last season.
"Being addicted to anything, it's hard to break loose," he said. "But afterwards, I was hungry and trying to do what I had to do to stay hungry and stay focused. It was tough, but I've got a lot of good people around me.
"It's always a great thing to come out of something and succeed in anything you do."
His performance against Fort Myers proved what he's capable of. Now, he plans to use Tuesday's start as a building block.
"I'm just going to stay here, do what I have to do and take what I did tonight into my next start," he said.
Mason Kelley is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.