A third-round draft pick from Michigan, Manningham suffered a hip flexor on his left side running a pull-up pattern early in the morning workout.
Manningham said the injury happened because he did not run his pattern right.
"It ain't nothing bad or serious," Manningham said. "If it was serious I would not be walking."
Woodson pulled a quad muscle in his left leg a short time later. The injury happened as the sixth-round draft pick from Kentucky was scrambling to his left during an 11-on-11 drill.
"I don't know what happened," Woodson said. "I'm kind of disappointed I'm not out there for my first minicamp. I just can't wait to get back out there and do some good things."
Woodson threw an interception on his first pass in minicamp on Friday, but he felt he improved a lot in the second workout in the afternoon.