Pettitte said he threw about 55 pitches on flat ground at U.S. Cellular Field, including 15 with him lifting his leg and wearing spikes, as the 40-year-old moves closer to ascending a pitcher's mound.
"I don't think they're going to let me get on a mound yet," Pettitte said. "I think probably just a little bit more pushing off, a few more pitches and stuff like that.
"I probably didn't even push off 100 percent today. I know I was pushing off harder than I was the other day. I'm still being cautious. I knew they weren't going to let me get on the mound on this trip, so I just don't want to have anything to set me back."
Pettitte plans to throw again on Saturday in Cleveland and is encouraged as he continues to come back from a fractured left fibula suffered in a June 27 start against the Indians.
"I feel good," Pettitte said. "I'm trying to draw a fine line here, because obviously I'm not completely healed or they would tell me I could get on a mound right now, I guess. There's no sense even trying to explain it. I wish I could tell you that I could go out there and run sprints and run around and get on a mound right this second, but I'm definitely not quite there yet."