Knights last week announced a special offer which has seen entry prices at Castle Park slashed to just £1 for this weekend’s game.
Fans must buy their tickets online by midnight tonight to take advantage of the one-off deal.
Knights held on to fourth spot despite losing 24-6 at Yorkshire Carnegie on Friday night.
They face a Cornish Pirates side currently lying eighth in the table - but victory for the Pirates could see them leapfrog Doncaster in the standings.
Just six points separate Knights and 11th placed London Scottish.
For more information about the £1 ticket deal visit www.drfc.co.uk.