Thanks to a much-improved roster, the San Francisco 49ers didn’t sign a large undrafted free agent class. This could be due to the number of, or lack thereof, rookies the team could bring to their offseason workouts, too.
Either way, we only saw a few names connected to the Niners once the draft was complete. One of those names was Ohio State linebacker Justin Hilliard, another player who participated at the Senior Bowl.
Pro Football Focus listed the top-10 undrafted free agent signings of the 2021 NFL Draft, and Hillard was sixth on the list:

6. LB JUSTIN HILLIARD, SAN FRANCISCO 49ERS
A five-star recruit out of high school, Justin Hilliard was supposed to be the next big thing in college football after receiving over 35 scholarship offers from top-tier programs. Unfortunately, injuries derailed his first two years as a Buckeye, and it wasn’t until 2020 when we finally saw him on the field for an extended period of time.
Hilliard was Ohio State’s best linebacker last season. He recorded an 80.0-plus PFF grade in run defense and coverage, eventually earning a third-round grade from PFF’s Mike Renner in PFF’s 2021 NFL Draft Guide. The bottom line on Hilliard’s scouting report reads: “If he stays healthy, Hilliard has an all-around skill set that can fit in any scheme at the next level.”
The 49ers lost defensive coordinator Robert Saleh, so it is uncertain whether the defense will have the same prowess it once did, but Hilliard should be a much-appreciated addition, especially with his value as an undrafted free agent.

Sports Info Solutions ranked Hilliard as the eighth-best weak-side linebacker in the draft and gave him the same grade as his college teammate Pete Warner, who was selected No. 60 overall:

Hilliard has a long history of injures some teams may not be able to get past, but he still has a solid skill set and high motor to be a versatile reserve.
Hilliard projects as a backup linebacker in the NFL who could play as both a Will and Mike. His size and coverage comfortability profile better as a Will, however. He has struggled with injuries through his career but he still has the athletic skill set to make an impact on three downs if he stays healthy. His speed and toughness should be valued on kickoff and punt teams.

Unless Samson Ebukam starts at SAM linebacker and switches to edge rusher in sub-packages, the third linebacker who starts for the 49ers will be an undrafted free agent. It’ll come down to Azeez Al-Shaair, Demetrius Flannigan-Fowles, and Jonas Griffith. San Francisco signed Nathan Gerry from the Eagles, but he was one of the worst coverage linebackers in the NFL last year.
Hilliard has an uphill battle, but he won’t be competing against draft picks who were selected early. His goal should be to earn a spot on special teams before eventually carving a role out for himself on defense.
That should be the goal of the majority of Day 3 draft picks and UDFA’s.