Orthopedic specialist Steven Copp determined that Peavy, who was diagnosed June 12 with a tibialis posterior tendon strain, needs 10 to 14 more days in his cast. The verdict is in line with original projections that Peavy would require about a month in the boot.
Peavy did not rule out the possibility of surgery, instead saying he hopes "it's not even an option" once the boot is removed for another evaluation.
"You walk around pain-free in this boot, and it's immobilized, and you think you're going to get out of there and feel good, but it wasn't quite where we wanted it to be," Peavy said. "We're halfway through what [Copp] told me would have to happen. Progression is good."
Peavy originally injured his ankle while running the bases May 22 against the Cubs. Doctors treated him for tendinitis, and he took to the mound with a heavily taped ankle for three starts after he sustained the injury.
But when an MRI on June 12 revealed deeper damage, the Padres placed Peavy on the 15-day disabled list, retroactive to June 9.
Peavy repeated the same strength tests Tuesday that he performed more than two weeks ago at his original evaluation.
"We took the boot off, and I was able to move it around [to test] certain positions that have caused me pain," he said. "We did some resistance stuff to test the ankle. I'm not completely pain-free, but it's certainly significantly better than a few weeks ago."
Padres manager Bud Black, who had not yet spoken directly to Copp, said it's too early to speculate on Peavy's rehabilitation until the cast is removed again.
"What the doctors indicated to Jake is that it looks as though it is progressing and healing to a certain extent," he said. "If that's the case, come another 10 days to two weeks, the walking cast will be removed, and he'll start the program of reconditioning himself to get back on the mound."
Doctors cleared Peavy to ride a stationary bike while still wearing his boot, and he will add some cardio workouts to his daily routine, which includes ultrasound therapy.
"I think as an athlete, you want to get out there, and you think you're immortal to certain injuries and you think you can press through injuries," Peavy said. "I'm not any different than any other person who has a break or a torn tendon. It's going to take time."
The 2007 National League Cy Young Award winner is 6-6 with a 3.97 ERA in 13 starts this season. Peavy is the Padres' all-time strikeout leader and is tied at second place for the most wins in team history.
Amy Brittain is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.