Biggest shoes to fill: Washington

Starters in, starters out. That's college football. Players' eligibility expires, and they leave for the rest of their lives, whether that includes the NFL or not.

And they leave behind shoes of various sizes that need to be filled.

Our concern with this series? The biggest shoes -- in some cases Shaq-like size 23s.

Biggest shoes: Running back Chris Polk

Polk earned first-team All-Pac-12 honors and finished third in the conference in rushing in 2011, earning a No. 9 spot on our list of the top-25 players in the Pac-12 this past season. He rushed for 4,049 yards during his career, which ranks No. 2 on the Huskies' all-time list. He scored 26 touchdowns along the way and -- oh by the way -- caught 78 passes. But he's off to the NFL. He leaves behind huge shoes, particularly if the Huskies want to remain balanced, instead of relying entirely on quarterback Keith Price.

Stepping in: Running back Jesse Callier

Callier is not unlike Oregon's Kenjon Barner. He's been a capable backup to a superstar for two years, as Barner backed up LaMichael James for three seasons. The 5-foot-10, 203-pound Callier has rushed for 693 yards -- 5.6 yards per carry -- and caught 25 passes over the past two seasons. He's also seen extensive action as a kick returner. He's looked good at times, but not spectacular. He will get the first chance to prove he's an every-down, 25-carries-a-game guy. But he will be pushed by sophomore Bishop Sankey and JC transfer Antavius Sims, who is likely to play a hybrid running back/wide receiver role. No matter what, Callier won't get all the touches, just as Polk didn't. But it will be up to Callier to take over as the showcase back, instead of becoming a 1A with another runner becoming 1B. Or the Huskies could be going with the proverbial "running back by committee."

You can check out the rest of the "Big Shoes" series here.