Seau, though, is the nephew of late Hall of Fame LB Junior Seau, and bears a striking resemblance to his uncle. Because of his bloodlines and relentless motor (someone needs to be a "high-motor" with Chris Long gone), Ian Seau provides for at least an intriguing storyline coming into training camp.
Seau's measurables, on the surface, look adequate for a 6'3 250 stand-up LB: 4.68 40, 34 1/2 vertical, 22 reps of 225 lbs. His production was not too shabby: forced 8 fumbles in his career, with 105 tackles and 18.5 sacks to boot. He clearly has some athletic ability, straight-line speed and some core strength.
Why did he go undrafted, then?
His short shuttle (4.51) and 3-cone (7.63) would have put him near the bottom of LB NFL Combine performers, meaning his ability to redirect is very limited. As a space linebacker, this is important. Per Lance Zierlein of NFL.com:
Stiff-legged pass rusher whose technique must be on point due to lack of reactive athleticism....Might be too stiff and slow to play in space as outside linebacker.
Zierlein's assessment of Seau shows that it might be difficult for him to find a role in the Rams' defense, unless he can turn some heads in camp by simply doing everything that is asked of him.
The Rams have Seau wearing #72, which can indicate that he is penciled in as a defensive lineman. He projects very similarly to the Rams' OLB Akeem Ayers, a player that flashed pass-rushing ability with the New England Patriots and now plays strong-side LB for the Rams. Ayers had a 4.28 short shuttle and 7.49 3-cone at 6'3 254.
The Rams don't have a lot of depth at outside linebacker (Ayers, hybrid linebacker/safety Mark Barron, and a group of inexperienced question marks). The Rams drafted OLB Josh Forrest in the 6th round, but he is a converted wide receiver and still has room to grow.
Seau could certainly find a way to stick with the Rams.
Chances of Making Final Roster (3/10)
I think Ian Seau will make a great practice squad candidate, with his relentless demeanor and ability to be groomed into a potential replacement for Akeem Ayers as a stand-up LB with pass-rushing ability.