TBC is, or will be, a good outside linebacker, but he is not Vrabel good. I believe the reason he was not used till now as an every-down linebacker is because he has trouble setting the corner in run support. Vrabel was very good at this - obviously, because he has the run skills to play inside. Whether the D can maintain their excellent run average with TBC in for Vrabel and Vrabel in for Seau should be looked into going forward. When Seau was in today the run D was nasty - Jones was going sideways and the Bears had to go to Benson to get beyond two yards a carry in the first half, and Benson had to run like someone asking for a concussion. When Seau was out, Chicago started riding Jones.
What makes you think TBC replaces Vrabel? I haven't gone to the tape yet, but my memory is Colvin's pressures came off the right side. This is pretty much what I expected would happen, TBC is going to take the majority of his snaps lined up next to Seymour and Colvin will be alongside Warren - odd isn't it, BB moves his OLB experience left to right, makes you think there is madness to his method.
As for TBC and run D, I get a kick out of people fretting over that. He is a converted 4-3 DE, his job at OLB vs. the run hasn't changed since he was converted to DE from LB in college - he is supposed to set the edge, nothing new for him,except that he gets to pay alongside Sey. BB has said it often enough to be an "it is what it is" remark, but the #1 transition for a DE converting to LB is pass defense. Watching TBC this year, I don't see any great weakness in his game, certainly no greater weakness than Colvin's ability to set the edge against Oakland last season (game 1 for the memory challenged), by this time last season Rosey was drawing double-teams playing LOLB with Vrabel inside. TBC actually looked better against the run than Rosey did to start last year, he's got a fighting chance to be fully tuned up by playoff time.
As for Vrabel being a run stuffer, he was just fine in the last third of last season playing alongside Tedy and behind Sey, Vince, and Ty. He and TBC both get to practice at game speed against such great teams as Detroit, Miami, Tennessee, Houston, and a Jacksonville club that isn't making the playoffs. So five non-playoff caliber tests, but pretty decent training opportunities.
We might complain that Chicago moved the ball in the second half, but if you buy the bogus PI theory, you can't say the Bears were overwhelming with their offense against the Vrabel/TBC defense. And if you don't buy it, you are left with speculation that those two passes would have been completed and the fact they would still not have been enough or a direct result of a sieve-like run game.
Bottom line, an offense that has had some success wasn't able to get much done against the Vrabel/TBC defense featuring two reserve Safeties - I don't see any team between now and the playoffs who can match the Bears' offense. Lets panic after we reach the playoffs and see if a playoff caliber offense can move the ball at will against the D.