I think Zidane is the only immediately available manager, unless they have tapped up Jardim who may be looking for a way out of under-performing Monaco. Doubt Poch will be interested right now, especially with a new stadium and having possibly the Madrid job open up in the summer. Conte would be an interesting choice but based on his last season at Chelsea, he is another manager capable of losing the dressing room similar to Mourinho.
Or could they give it to Carrick in the short-term, hope results come through, and then go for a manager in the summer? Incredibly risky but with a better payoff.
Interesting times ahead.