ESPN.com's Bruce Feldman has ranked the top-10 "impact true freshmen," and USC receiver George Farmer ranks third. Here's what Feldman wrote about Farmer:

3. George Farmer, WR, USC Trojans:

If, as many Trojans insiders insist, Farmer is even more talented than his buddy Robert Woods, Matt Barkley is going to have a startling array of firepower to work with (don't forget about former blue-chip WR Kyle Prater, who redshirted in 2010). Farmer has blazing speed, and at 6-foot-2, 205 he has a very strong, sturdy frame to go with it. With him in the lineup, defenses will be seriously tested, having to cope with Farmer's speed and Woods' explosiveness at the same time.

Woods was dominant this spring, but many expect Farmer to be Woods' equal this fall. We'll see. If so, Barkley and the Trojans might not need much of a running game with their patchwork offensive line. What about the other 11 Pac-12 teams? Who is the most likely impact freshman for each? Because of our "heck yeah!" attitude, we've decided to take a stab at this query. Understand that it's not just about highly rated, it's about who might help immediately.

Arizona: The Wildcats signed three touted linebackers, but we're tapping Rob Hankins as the one who will make the most impact -- and by impact, we mean start. While Hankins is a pure inside linebacker, the Wildcats need immediate help on the outside due to Jake Fischer's knee injury.

Arizona State: With so many returning starters, the Sun Devils won't need a true freshman to start immediately. But after the knee injury to Omar Bolden, cornerback went from a position of strength to a questionable one -- at least in terms of depth. So the best guess is Rashad Wadood will get an early opportunity to work his way into the rotation.

California: The Bears reeled in an outstanding class, particularly on defense. A number of those guys are going to play. But a need area next fall for Cal is running back, where 5-foot-7, 188-pound junior Isi Sofele is atop the depth chart. So we're tapping running back Brendon Bigelow as the impact freshman, with the caveat that he is coming back from a knee injury. If not Bigelow, then perhaps it will be Daniel Lasco.

Colorado: The Buffaloes lost two starting corners to the NFL and struggled against the pass in 2010. They need help in the secondary, and Sherrard Harrington looks like the best bet, either at cornerback or perhaps at safety.

Oregon: Colt Lyerla is going to play for Oregon next fall, likely as a hybrid tight end/H-back sort. But the Ducks are solid at tight end. They need either Devon Blackmon or Tacoi Sumler to step up as an outside receiver. We're going with Sumler who has special speed and is more polished as receiver.

Oregon State: Rusty Fernando was penciled in as a starting defensive end at the beginning of spring practices, and it appears it will remain that way. But he's a junior college transfer. So, in the interest of focusing on incoming freshmen, we're going with Terron Ward, a grayshirt freshman running back who flashed ability this spring. At least one of the three true freshmen running backs figures to get touches.

Stanford: Linebacker James Vaughters is a beast. His film will give you goose bumps. He's going to play. But in terms of need, receiver is a far more questionable position for the Cardinal this fall. So watch out for Ty Montgomery.

UCLA: A lot of UCLA fans would say quarterback Brett Hundley. He finished No. 3 on the depth chart after spring practices and, while he's the quarterback of the future, it likely would be better to redshirt him, if possible. But Kevin Prince's inability to stay healthy and Richard Brehaut's inability to be consistent might make that impossible. And the Bruins recruiting class doesn't include any other obvious impact guys for this fall.

Utah: This one is easy -- running back Harvey Langi was No. 2 on the post-spring depth chart behind John White, and that competition is ongoing. Langi is going to get plenty of carries.

Washington: Another easy one -- Austin Seferian-Jenkins finished spring as a push with Michael Hartvigson as the Huskies starting tight end. Nothing suggested that he won't live up to the considerable hype he received during recruiting.

Washington State: Outside linebacker Logan Mayes has great Cougar bloodlines; he's the son of former Washington State All-American running back Rueben Mayes. He has the athletic ability and football smarts to work his way into the mix immediately, mostly likely at strong side linebacker.