The Co-operative Championship One will comprise just nine teams in 2013 after the Rugby Football League failed to find a fourth new club in time.
The League have already admitted Oxford, Hemel Stags and University of Gloucestershire to the third tier of the professional game and were hoping Coventry would take the place of Northampton, who withdrew their planned entry after admitting they were unlikely to be competitive.
However, the RFL have now conceded that Coventry, too, would not be ready in time and would instead look to bring them into the competition in 2014. RFL chief operating officer Ralph Rimmer said: "Coventry Bears have made significant strides in the last few years but our view is that it is too soon for them to make the transition into Championship One next season."
He added: "We have always maintained throughout this process that it was important not to rush clubs into the competition before they are ready.
"I spoke to the Championship One clubs directly a fortnight ago to make them fully aware of the options available. The clubs have been very supportive of the process."
The Championship will remain at 14 clubs as planned next season after four were promoted from Championship One to make way for the newcomers.