The Lions agreed to terms with four of their draft picks on Monday and they also announced the addition of a player who went undrafted last week.
The team signed linebacker Juwon Young and added him to their 90-man roster. They waived linebacker Tre' Williams in a corresponding move.
Young began his time in college at the University of Miami and spent two years there before moving on to Marshall. He had 85 tackles, 9.5 tackles for loss, three sacks and three forced fumbles in 21 games for the Thundering Herd.
Williams was undrafted out of Auburn last year and signed with the Jets, but a shoulder injury kept the deal from being finalized. He signed with the Lions earlier this year.