Doyle will be 3 months at best with all the modern recovery facilities available, i think someone like Lindgren could sign a short term deal to cover, I'll throw in Laguta just in case his no.1 fan pipes up.
As for Dan T its gonna be 8 weeks minimum I'd suggest so as suggested a Barker type replacement
RR for Doyle and a guest for Dan the best way forward until proper recovery times are known