Mancini’s take on rookie linebacker Perry Riley following Washington’s 42-17 drubbing of the Buffalo Bills on Friday night: Riley is a player, a smart defender who helps you win games…period. You saw that in his first preseason game as he flashed the ability to quickly diagnose plays, fight his way through blocks and deliver solid tackles that stop ball carriers dead in their tracks. The former LSU Tiger has powerful hands to beat his opponents in traffic and is bright enough to line up his teammates. He loves playing football and works hard at his craft, not to mention the fact that he’s an excellent special teams player. Riley will probably have to take a back seat to starters London Fletcher and Rocky McIntosh this year, but the intense 22-year-old believes he can also play outside just as he did back in college. Riley isn’t one of those guys