It seems that WWE intentionally overstated how injured John Cena really was when he took time off in August. His return against Alberto Del Rio at Hell in a Cell is three months earlier than he was advertised to come back.
When Cena was first examined by doctors in August, they found a partial tear in his triceps, not as bad as was initially reported. WWE has done this before as a way of surprising fans and showing that their superstars train hard to return sooner than a normal person would.
While Cena has been medically cleared to wrestle, there was still talk of keeping him out for a few more weeks to make sure he was 100%. Cena was cleared within the past week and the decision was made over the weekend to have him return at Hell in a Cell.
The match will be a traditional singles match, and Randy Orton vs. Daniel Bryan will be the only match inside the Hell in a Cell.