ATLANTA -- Tommy Hanson remains that special prospect, whom the Braves will continue to nurture in the Minors until the opportunity arises for him to assume a lasting spot in the Atlanta rotation.

With that opportunity still a few weeks or months away, Hanson will remain with Triple-A Gwinnett and watch from afar as his good friend Kris Medlen gains the first crack to test his talented right arm in the Majors.

Having spent the past five weeks dominating the International League, Medlen will make his Major League debut against the Rockies at Turner Field on Tuesday night. The 23-year-old right-hander will be starting in place of Jo-Jo Reyes, who will now assume a spot in the Braves' bullpen.

"We're looking at a small window," general manager Frank Wren said. "I think if we were looking at the long haul and there was a situation for a starter to come up and be a starter for the rest of the season, then it would probably be Tommy [Hanson]."

Medlen will likely remain in the Atlanta rotation until Tom Glavine proves that his left shoulder is healthy enough for him to begin pitching in big league games. While Glavine has said that he'd like to make a start before this month is complete, the Braves, who will owe him a $1 million bonus when he's placed on the active roster, may be more comfortable putting him in the Atlanta rotation after June arrives.

With this timetable, Medlen, who leads the International League with a 0.96 ERA, could be provided the opportunity to make at least three Major League starts before having to return to the Minors. The Braves didn't want to put Hanson in a position where they might be forced to send him back to the Minors after providing him his first taste of the Majors.

Hanson, who is widely regarded as one of baseball's top right-handed pitching prospects, will take a 1.99 ERA into his start on Saturday for Gwinnett. In 40 2/3 innings, he has registered 57 strikeouts, issued 13 walks and limited opponents to a .186 batting average.

While those numbers are impressive, they've been bested by Medlen, who has won each of his five decisions and recorded 44 strikeouts while issuing 10 walks in 37 1/3 innings. The youthful-looking hurler has limited opponents to a .152 batting average.

"It was really about who is throwing the best, and in Kris' case, he hasn't had a bad outing," Wren said. "Every time he's gone out there, he keeps getting better."

Medlen will carry a streak of 19 2/3 consecutive scoreless innings into a one- or two-inning appearance following Hanson against Buffalo on Saturday night. The tuneup outing will prevent him from making his Major League debut with seven days of rest.

"He impressed us during Spring Training, and he's been lights-out up there with Gwinnett," Braves manager Bobby Cox said. "We're excited to see him pitch."

Reyes, who is 0-9 with a 6.58 ERA in his past 18 Major League starts, believes that he could benefit from this move to the bullpen. He'll now join Eric O'Flaherty as the club's two left-handed middle relievers.

"I believe there is a role for everybody in this world," Reyes said. "Who knows? This might be a blessing in disguise, and this might have been my calling from Day 1. I don't know. I guess we'll find out."