The 49ers signed Greenlaw to a one-year, $7.5 million contract Thursday, Ian Rapoport of NFL Network reports.
Greenlaw spent the first six years of his career with San Francisco before signing with the Broncos last offseason. Greenlaw went on to miss more than half of the season due to quadriceps and hamstring injuries, appearing in just eight regular-season contests. He's made just 10 regular-season appearances across the last two seasons due to lower-body injuries. Greenlaw knows the system and is a veteran option for a linebacker group that dealt with a rash of injuries during the 2025 campaign.