The Buffalo Bills made a splash in free agency last spring when they signed Mario Williams, so naturally, all eyes were on the defensive end when training camp opened on Friday. Fortunately, he was everything advertised.

But some other Bills are making impressions, too. Some were acquired through the draft, and others came with more experience under their belt, but they all could have a major  impact on the 2012 season.

C.J. Spiller. Sure, Fred Jackson is the starter, but he's getting older, and Spiller averaged more than five yards per carry last season. It may be hard to keep Spiller off the field, and this might be the year we see why he was drafted first by the Bills.

Stephon Gilmore. Combine a freakish pass rush with a steady cornerback, and you might see lots of turnovers from this squad. Gilmore is already receiving high praise from the Bills best receiver, Stevie Johnson, and comes in with a reputation as a physical corner. The biggest question mark is his recover speed.

Cordy Glenn. So much noise was made about the Bills first draft pick that it's easy to forget that the Bills got exactly the player they wanted in the second round: tackle Cordy Glenn. Right now, he's alternating the starting position on the left side of the line, but you can bet the Bills want Glenn to be the starter.

Marcus Easley. He's a wild card at a crowded position battle, but he may be the Bills fastest receiver. A rookie year injury and a heart condition in his second season have kept Easley off the field, but he was the Bills best prospect last pre-season. Still, it's going to be tough to keep a roster spot. Donald Jones and Brad Smith are likely shoe-ins, so Easley will have to out-battle Derek Hagen, who's been impressive, and David Clowney for a roster spot.

Marcell Dareus. Dareus was the lone bright spot in the Bills defense last season. It's his second year, and now he lines up with Super Mario and some other guy named Kyle Williams, who made the Pro Bowl two years ago. No longer able to double team, Dareus could run wild in the opponent's backfield.

Mark Anderson. Anderson quietly signed with the Bills after Mario but may have as big an impact on the Bills pass rush this season. While Williams is the total package, Anderson is a pure speed rusher and had some real nice success in New England. Hopefully, Anderson's 10 sacks last season weren't just a product of Bill Belicheck's "genius" and he will continue to be impressive.