ATLANTA — Braves left-hander Tom Glavine threw three simulated innings Monday, another step in the 300-game winner's plans for a rehab assignment this week.

Glavine, on the 15-day disabled list with a tender shoulder, made approximately 50 pitches to teammates David Ross, Martin Prado and Greg Norton. The 43-year-old hopes his arm will be strong enough for an appearance Saturday at AAA Gwinnett.

"It's always good when you face hitters," Glavine said. "I think sometimes you get a false sense of security when you're throwing in the bullpen and nobody's swinging the bat on you."

Norton hit a liner off Glavine's left hip, but the pitcher wasn't concerned that his comeback will be affected. The cranky condition of his shoulder, which caused Glavine to seriously consider retirement last month, has been the problem.

"A lot of the issues I had in spring training are gone," he said. "My issues were in the back (of the shoulder) where they shaved my spur, on top where they did my bursa sac, and the front where I've always had problems and they didn't do anything. Now it's basically just the front when I'm swinging the bat."

Glavine, who has a 305-203 career record with a 3.54 ERA, doesn't know if he will have any at-bats in the rehab assignment. When he wakes up Tuesday, Glavine should have a better idea about the condition of his shoulder.

"The biggest thing I worry about is how I'm going to feel the next day," he said. "I'm more concerned about that than about cranking it up. I'm not going to sit here and tell you that I'm pain free, but I've got to go out there and find out what I'm going to be able to handle, and if it's responding well enough for me to go out and pitch in a game."

Last season, Glavine's 21st overall and first with Atlanta since leaving as a free agent and pitching from 2003-07 for the New York Mets, was difficult. The two-time Cy Young Award winner had never been on the DL in his career, but he appeared in just 13 games, all starts, with a 2-4 record and a 5.54 ERA.

A sore hamstring sidelined him last April, and Glavine landed back on the DL June 11 with a left elbow strain. His season ended with a third trip to the DL Aug. 15, soon after which had a torn flexor tendon repaired by orthopedist James Andrews. Glavine also underwent a shoulder procedure.

Glavine couldn't gauge the speed of his fastball, which he hopes will be between 83 and 84 mph at Gwinnett. Pitching coach Roger McDowell, who stood behind Glavine during the session, saw no need to use a radar gun.

"When I made bad pitches up over the plate they put good swings on them, and when I got the ball down or got the ball in the corners, they didn't take as good swings," Glavine said. "That's a good sign for me. I just need to get a little more consistent with that."