Some people believe Kovalev is a front-runner. I wouldn't go there yet. Even if it were true in order to beat a front-runner you have to actually be in front. While I don't think Froch gets totally steamrolled, I doubt his toughness alone is enough to overcome the power difference for 12 rounds. Froch absorbs some shots and gets in own but is forced on the defensive more often than he can handle.
Froch just is not a legit 175lbr and it's worth remembering that Kovalev plain beat a guy who beat Froch, and annihilated a guy who gave Froch a really close fight. Kovalev because he's bigger, hits harder and Froch is just too hard to not hit cleanly.