The Knights have announced a temporary groundshare deal with Rovers and Club Doncaster, ahead of the first leg of their promotion play-off semi-final at Yorkshire Carnegie on Sunday.
Their Castle Park base would currently fail to meet basic standards set by the RFU and Professional Game Board (PGB) to host Premiership rugby with the ground’s capacity falling well short of the set 10,000 minimum.
But an agreement has been reached with Club Doncaster for the Knights to become the fourth sports team to use the Keepmoat, following Rovers, the Dons and the Belles.
The arrangement would be temporary with the Knights set to immediately begin work on bringing Castle Park up to standard if they were to secure promotion.
The Knights have begun talks with Doncaster Council, emergency services and the RFU/PGB over changing Castle Park’s safety certificate in order to allow the installation of temporary stands to bring the capacity beyond 10,000.
In a statement released last night, Club Doncaster said the agreement for the Knights to use the Keepmoat covers a maximum of six fixtures. This suggests Knights officials foresee work being completed at Castle Park before Christmas.
Rotherham Titans carried out similar work on their Clifton Lane home when they achieved promotion to the Premiership in 2000.
A potential two-legged final against either Bristol or Bedford awaits if they are victorious over two legs against Carnegie, with the winner heading into the Premiership.
A play-off triumph does not always guarantee promotion with the RFU and Professional Game Board (PGB) setting a minimum standards criteria (MSC) for the top flight.
Castle Park currently falls shorts of the MSC in a licensed capacity but the Keepmoat has been passed by the RFU and PGB.
For Castle Park to be granted a license by the RFU and PGB, work would have to be complete to standard by the first week in September, giving the club a 14 week window following the second leg of the play-off final.
In a statement, the Knights said such a turnaround would not be possible.
It read: "Aside from the huge expense of speculatively doubling the seating and terraced capacity of Castle Park before the outcome of the playoffs was known, the time constraint between one season ending and the next beginning made it impossible to guarantee that Castle Park would be up to standard by the start of the new season."
The club statement concluded: "We trust that we can rely on the loyal support of the Doncaster Knights fans during these exciting times at the club."