The two-time Cy Young Award winner opened the season on the disabled list because of a sore left shoulder and said this month he wasn't sure he will pitch again.
He threw in the outfield for the second straight day before Tuesday night's game against St. Louis. He planned to rest then throw from a longer distance on Thursday and off a mound next week.
Glavine was 2-4 with a 5.54 ERA in 13 starts last season. He had offseason operations on his left elbow and shoulder.