The names of new signings and those players who are staying or leaving will soon be made public.
It will also be confirmed that coach Steve Boden, who has enjoyed such a successful season at the helm, has been rewarded with a new contract.
Doncaster may well have lost the first leg of this Championship Cup tie, going down 26-24 in a contest in which both sides scored four tries, but they are still in the competition.
However, winning the return match in Penzance a week on Saturday is the toughest of challenges.
Showing several changes, Doncaster were well below par but fought back from being 19-5 down to 19-19 on 74 minutes following a penalty try and a try by replacement hooker Will Holling, converted by Billy McBryde.
But in a thrilling climax, Pirates scored a fourth in the 78th minute when full back Alex Cant intercepted a pass and, after fly half Harry Bazalgette put over his third conversion, the visitors regained the lead at 26-19.
Doncaster recovered again two minutes later as their pack won possession close to the Pirates’ line, and on this occasion another replacement forward, Thom Smith, was the beneficiary of the powerful drive.
Surprisingly, Doncaster were suddenly only two points away from retaining their proud unbeaten record which would be intact if fly half McBryde could earn a draw with an accurate conversion.
Unfortunately, the Welshman’s kick flew wide.
Doncaster skipper Sam Graham said: “We are determined to go down to Cornwall to give a better account of ourselves. We are taking the Cup seriously and after the season we’ve had, this defeat makes it all the more disappointing.”
Doncaster Knights: Best, Evans, Edwards, Strachan, Davey, McBryde, Wheeldon (Green 45), Wrafter (Usher 64), Roberts (Holling 63), Connolly (Paul 49), Peters (Smith 72), Murphy (Groves 64), Volpi, Davies (Kelly 70), Graham.
Cornish Pirates: Cant, Wedlake-Millecam, Tucker (Wyatt 64), Elderkin, Sirker, Bazalgette, Dawson (Schwarz 66), Phillips (Adkins 40),Channon, Rodman (King 18), Teague, Cutmore, Bolwell (Walker 64), Gibson, Kiri Kiri (Williams 70).
Referee: Charlie Gayther.