Greenlaw is unlikely to be ready for Week 1 after suffering a torn Achilles in February's Super Bowl defeat. San Francisco signed veteran linebacker De'Vondre Campbell in free agency to fill his position during any missed time.
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Hufanga tore his ACL in November, causing him to miss the end of last season and the 49ers' playoff run. Despite this setback, the safety is optimistic about his return.
"The goal is to be ready by Week 1," Hufanga told reporters in June. "The goal is to be in training camp, not at the very beginning, but to ramp me up correctly, just so it's not throw you out there to the wolves and good luck. But trying to be smart with it."
Speaking to reporters today, general manager John Lynch added that defensive lineman Drake Jackson will also start on the PUP list. He has yet to be cleared after undergoing patellar tendon surgery.
Rookies reported to training camp last week, while the veteran players reported today. The 49ers plan to hold their first training camp practice on Wednesday at 10:25 a.m. PT.