Brian Stewart, Ron Zook and Zohn Burden will join Mike Locksley on the sidelines.
Campbell led the Terps with 10.5 sacks per game in 2020.
Brian Braswell is also joining Mike Locksley's staff as the Terps' new offensive line coach.
Offensive line coach John Reagan has also left College Park.
Lewis is the highest-rated inside linebacker in the 2021 class.
The Terps also secured wide receiver Marcus Fleming as a transfer from Nebraska.
Funk rushed for 516 yards and three touchdowns this season.
The move was made due to a pause in team activities, which was caused by a COVID-19 outbreak.
The Terps reported 15 positive tests from athletes in the week of Dec. 10.
The recruiting class is led by four-star linebacker Demeioun Robinson.