Pettitte has been sidelined since July 19 with the injury, which was originally estimated to knock the veteran out for up to five weeks but has now taken longer. Pettitte threw a 35-pitch bullpen session on Sunday in Chicago and reported that he was pleased with his health.
"We've come so far -- there's no sense in not being extremely careful," Pettitte said. "I'm not going to push it. Whatever they think, I'll do."
If Pettitte's session on Wednesday goes well, he would then be escalated to face hitters, either under controlled conditions in a simulated game or during a Minor League rehabilitation assignment. Pettitte has estimated that his best-case scenario would be to return within two weeks.