That is really a shame. So now it makes sense why they signed Derrick Moncrief. He went undrafted in the NFL but played in the CFL where he was a standout. What I like about him is he has excellent speed (4.5) and showed coverage ability in the CFL. For whatever reason, he was released by the Raiders this year and worked out and signed by the Rams. Last year Moncrief had an impressive year in the CFL, tallying 73 tackles, with 4 sacks, 3 INTs, and a FF.
I feel that Moncrief will take that #3 ILB position with his speed, and production in the CFL. That final, spot will come down to Reeder, Rozeboom, and Johnston. Reeder has the experience and although his play was inconsistent last year, it's not something that is unexpected from a raw rookie. If he built on that experience and showed well in camp he might make the cut. Rozeboom comes in as raw as most rookies but with good athleticism. He's got good speed for the position and showed impressive production last year in college, with 111 tackles with 6 TFL and 2 INTs. Both he and Moncrief fit the mold of what they seem to want at LB with speed and athleticism. Johnston though drafted, and is a fan favorite with his enthusiasm probably comes in the rawest of the bunch. Even if he doesn't make the cut I think he's a lock for the PS because he has upsides if he trains properly next offseason.
Personally I see the ILB position as now being Kiser & Young starting. Moncrief and Rozeboom in rotation and Johnston going to the PS.