I love Ryan Day, but he’s not gonna always be truthful and I’m totally fine with that. It would be irresponsible to always be honest with the media. From another article on 11W:
One day before the Big Ten Championship Game, Day said Fields “had a good, strong week of practice” and that it wouldn’t affect Ohio State’s play-calling against Wisconsin, describing his quarterback and “100 percent go and he’s ready to roll.” At the time, Day said Fields’ knee injury – which the quarterback himself said was a sprained MCL – was “very different” than the knee injury J.T. Barrett battled through to play in the conference title game two years earlier.
In that game itself, though, it was evident that Fields was hobbled, as he had his worst game of the season as a runner (a net gain of one yard on 12 rushing attempts or sacks) and wasn’t able to extend plays with his feet the way he had for most of the regular season.
Asked again about Fields’ knee injury on Wednesday, Day revealed the truth: Fields “really didn't practice much at all and wasn't able to do much” in the week leading up to the Big Ten Championship Game, meaning Ohio State’s quarterback was in a situation that was actually “very similar” to that which Barrett faced leading up to the 2017 Big Ten Championship Game against Wisconsin after suffering a knee injury at Michigan one week earlier.