The choice of the Bears made to take Chris Williams over Rashard Mendenhall has always been seen as a question of need versus talent, but if you check out this article it looks like there was more to it.
7. At least one key member of the Chicago coaching staff had rookie RB Matt Forte ranked higher than former Illinois RB Rashard Mendenhall.
A league source told Scout.com that when Matt Forte went through his paces at a private workout for Chicago and showed his football intelligence during a film session, at least one influential member of the coaching staff was set on adding him to the roster over Mendenhall.
So even though Mendenhall was available to the Bears when they made their first pick at No. 14 overall, they opted to select OT Chris Williams instead. That allowed the Steelers to snag Mendenhall at No. 23. Chicago patiently waited until the 13th pick in the second round and still got the running back it wanted.
Forte's a calm, focused young man who takes this game very seriously. He runs strong inside the tackles, has the agility to get around the end, and is a skilled receiver. And with an unstable quarterback position in Chicago, Forte's willing and skillful blocking should help the Bears complete a few more passes to their receivers and tight ends. Don't be surprised to see him win the starter's job during training camp, or by the midpoint of the season at worst.
I don't know who counts as influential on the coaching staff, but in the Bears opinion they didn't miss an opportunity, they just got the guy they liked best at a better spot in the draft.