Malan said the forecast was for rain from 3pm but it all went awry from the morning and wasn't expected to clear until midday today.
CD have opted to go with two spinners in Tarun Nethula and Ajaz Patel on the understanding the pitch will offer them some purchase on day four.
Malan said the Stags were taking the momentum they had found in their second innings at McLean Park against the Firebirds.
Seth Rance, of Wairarapa, comes in as a right-hand seamer who has the ability to shape the ball into lefty-heavy Otago batsmen.
"Rossy [CD director of cricket Craig Ross] identified Seth after seeing him play a few games," he said of the 26-year-old who made his first-class debut in 2008-09 but became a notable absentee after 2010-11 after doing well in the white-ball formats.
"He just got married a few days ago and is a bit older so cricket isn't everything for everybody," Malan said, adding Rance offered an exciting alternative to skipper Kieran Noema Barnett and opening seamer Bevan Small who shaped the ball away from right-hand batsmen.
CD have released Roald Badenhorst for Manawatu's Hawke Cup challenge match against the bay of Plenty this weekend.
Stags prospect Joey O'Connor, of Nelson, has stepped in as 12th man.
Elsewhere, Auckland limited a fast-starting Canterbury for day-one honours at Hagley Oval.
Rain also affected the Firebirds v Northern Districts Knights game at Karori Park.