The focus of attention this week has been on the man replacing Brian Urlacher at middle linebacker. Less has been on the man replacing Nick Roach.
And against the No. 1 running back in football, Geno Hayes looms as a more vulnerable fault line in the defense than Roach-for-Urlacher.
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This is not my first time around, Hayes insisted. Its not my first rodeo.
For NFL purposes, however, it pretty much is. Hayes is a career weak-side linebacker.
And sources told CSNChicago.com in training camp that Hayes, never a strong-side linebacker in his career, was initially something of a disappointment despite having come from a Tampa Bay scheme similar to the Bears. At one point, coaches tried Blake Costanzo at middle linebacker, leaving Roach in his usual spot and Hayes on the bench.
Hayes eventually established something with extensive preseason playing time, important now because he has never started a game at that position.
Now he starts there with exactly 48 defensive snaps this season and at 226 pounds, vs. Adrian Peterson, who is taller, faster and nearly as big as Hayes.
The problem becomes compounded because the Vikings have used 248-pound fullback Jerome Felton on 36 percent of their snaps this season.
And as the strong-side linebacker, Hayes' base position will be opposite tight end Kyle Rudolph, 6-6, 259 pounds and rarely off the field (725 of 788 Minnesota snaps).
How much Hayes picked up in his preseason time will be on display Sunday afternoon.
It was great getting good experience in the preseason, getting accustomed to the defense, accustomed with the guys. I was out there playing ball day in and day out. So, it was great. Its part of my job description.
Now it is his job description.