Weak-side linebacker Perry Riley started 22 games for the LSU Tigers in 2008 and 2009 and became a leader on that fine defense by his senior season. Although he played outside in college, the 6'1" and 240-pounder projects as an inside linebacker in the NFL. Riley is weak against the pass and showed an tendency to bite on fakes and good play-action pass calls. What's more, he's not fast or quick enough to react quickly and change direction so he can recover and still make a play. He's much better playing in a zone defense against pass plays.
However, Riley is very stout against the run, reacting quickly and able beat blockers to the point of action. He's got excellent balance and shows good movement from side-to-side [lateral mobility] and has the strength and power to fight through trash and tackle running backs. He's a hard worker with a good motor so he runs hard and doesn't give up on plays.
He'll need to move inside as a pro because he will really struggle badly against NFL running backs and tight ends, but he's a solid tackler in traffic or the open field and he takes good angles to the ball-carrier. Don't expect him to light people up like Ray Lewis or the late Sean Taylor -- Riley specializes in just getting guys to the ground, not making ESPN highlight reels. He's not a pass-rusher, as he has never really shown any moves or the kind of blazing speed he would need to get around NFL tackles and tight ends.
SUMMARY: Right now Riley projects as a special teams contributor and backup inside linebacker who may be able to start eventually. He needs to work hard on his read and react against the pass, but he's already a very solid tackler and run defender.