"Best friends again," Medlen said, laughing. "We've got one rental car, so we can't leave each other's sight."
Hanson, who threw his final bullpen session on Saturday, will pitch in a simulated game on Monday and throw 35 pitches in two-to-three innings.
"We'll just have to take it a step at a time and see how he comes out of that," said manager Fredi Gonzalez.
Gonzalez has said that he would like Hanson to make at least one regular-season start before he can truly be considered an option for the National League Division Series. But he said on Sunday that Hanson will likely need more than one rehab outing in Orlando in order to build up innings.
"You could do all that speculating, but if he comes up and says he doesn't feel good, we back off," Gonzalez said. "That's why we've got to take it in steps.
"In a perfect world, we would like for him to throw a game. I don't want to get into a perfect world, because we're still not sure."
While Hanson is pitching his simulated game Monday, All-Star pitcher Jair Jurrjens will throw off the mound for the first time in Miami before the Braves face the Marlins. Jurrjens, who has been out with a sore right knee, hasn't pitched for Atlanta since Aug. 30.
Jurrjens is not likely to pitch in the first round, but he may be an option for the NLCS if the Braves make it that far. He said on Monday that he realizes he may not pitch again in 2011.
Medlen will follow Hanson in Orlando by pitching on Wednesday and Thursday. That's all he'll likely need before returning for the final series of the regular season against the Phillies.
Medlen -- who hasn't pitched this season after undergoing Tommy John surgery last August -- has been encouraged by each of his live BP outings.
"I thought it was so much better [than Saturday]," he said. "I didn't start guys off with fastballs, intentional walk-style. I was way more around the zone. I made the corrections with my curveball. The curveball felt better today, and the changeup felt good, too.
"Overall, it was a lot better than yesterday, even though yesterday was good."
Joining Medlen and Hanson in the Instructional League could be left-hander George Sherrill. The reliever has been out with elbow inflammation, but he threw his first bullpen session on Sunday. He didn't believe he would need to make a rehab appearance in Orlando, but Gonzalez said it was an option.
"It's probably not going to feel the same until I pick up a ball in January," Sherrill said. "It feels good enough to come back, but it doesn't feel like [it did in] May. But I think it's good enough to come back and get some people out. I'm feeling better each and every day."
The trio may not be the only Braves in the Instructional League. Gonzalez said outfielder Nate McLouth is getting close to heading to Florida to "start doing some stuff," but he's still a long way off from returning to the club. McLouth has been out since undergoing sports hernia surgery on Aug. 5.
"That Instructional League team is going to be pretty good," Gonzalez said.