Reacquainting himself with the altered delivery he developed in January, Hanson experienced no problems during a 30-pitch bullpen session on Wednesday.
"I think I threw a little better than I had expected," Hanson said. "I've had some time to think about some mechanical stuff. I was surprised by how well I threw."
Hanson could be cleared to begin throwing live batting practice as soon as Friday. But he will have to first pass one more part of the concussion impact test, which tests reaction and memory skills.
"Hopefully, he passes that," manager Fredi Gonzalez said. "Or hopefully, he keeps failing it and the doctors understand this is just a normal thing."
Hanson has not experienced any dizziness or headaches for more than a week. His absence over the past week has likely increased the odds of Jair Jurrjens being the Opening Day starter.
But the Braves still believe Hanson will be ready to make his first start of the season.