It’s 100 percent the calf. Burrow didn’t just somehow forget how to play. The problem is that the only cure is rest, which is the one thing he isn’t going to get. Burrow has to adjust to it, Zac has to scheme around it and the rest of the team has to step up their play because their margin for error has dropped to little/nothing. Through four games they have struggled to do any of that, which is why they’re 1-3.