That has forced Citroen to rethink on several areas, notably the suspension and driveability, and team principal Yves Matton told Autosport it was now starting to ramp its work up ahead of 2018.
"We already took some risks with the development," Matton said.
"I told you already that since Sweden we have been working harder and harder and really looking already towards next season - this is where the focus is for the team now.
"But we know we have to take more risks and put more and more new parts on the car with less time for validation.
"This isn't the way things are done and it's the first time that we have really done this, but it's the only way we can work towards the timetable for the start [of next season]."
Swedish suspension firm Ohlins is working more closely with Citroen and the eight-time manufacturer champion has replaced technical director Laurent Fregosi, the man who designed the C3 WRC, with Christophe Besse, who had been involved with Citroen's early success in rallying.
Fregosi remains at Citroen, but returns "to a more technically focused role."
Citroen has been rotating drivers this season, benching the under-fire Meeke and drafting in ex-Volkswagen driver Andreas Mikkelsen for certain rallies.
Only Stephane Lefebvre has been confirmed for next month's Rally Spain, but Citroen must reveal its plans by next Tuesday (September 5), when entries for the Salou-based event close.