This loss is a mixed bag.
Negative. The center makes the line calls, he's arguably the most important lineman in recognizing and picking up blitzes. That takes experience, and has always been a strength of Fraley's.
Positive. Fraley has been the biggest reason the Eagles struggle against the 3-4 defense (good ones atleast). Plainly stated, he's undersized and cannot handle a nose-tackle lined up over him. The new guys are bigger/stronger and should be more able to handle nose tackles.
Their are actually 2 canidates to replace him: Darilek and Jackson.
Darilek - 2nd year guy, drafted in the 4th round, played tackle in college. He's been on the active roster this year, so he has that going for him. But before this year, he had never played center, is he ready?
Jackson - 4th year? Repeatedly injured and placed on IR year after year. This year, he got a minor injury and was put on the practice squad. The Eagles have always been high on him, Mayberry and other players identified him as a good prospect. He's got more experience at center than Darilek and knows the playbook better. But he's been running the scout team this year.
It's still up in the year. It could have a big impact in this game.