Since qualifying for their first bowl since 2016, the Terps have lost some contributors to the transfer portal.
Jacobs, a former four-star recruit, backed up Jake Funk and Tayon Fleet-Davis in his two years in College Park.
23 players missed the game in adherence with COVID-19 protocols.
Harrison suffered a season-ending knee injury against Penn State on Sept. 27.
Among other signings, coach Mike Locksley secured five-star wideout Rakim Jarrett.