After four matches, Otago is at the bottom of the competition table with just four points from a solitary win against Wellington in its opening match.
The Volts have made slow starts in the past, but with the round-robin trimmed from 10 to eight matches, they can ill-afford to drop another match and desperately need to beat Canterbury in Timaru today.
"We are in a position where it is a must-win game," Otago skipper Craig Cumming acknowledged.
"If we win this we get ourselves back into fourth spot, and with a bonus point we could end up third equal. So it is not the end of the world, but we certainly need to get some points.
"We've had a good talk after the last game about the areas we need to work on.
"We need to start better with the ball and do better in the power-play. The last game we gave up 68 runs in five overs, which was not good enough."
"Batting-wise we've been in every game but just haven't had anyone in the top five go on and get a big score. We've had guys play supporting acts, whereas we need someone to play a starring act."
Otago has made some personnel changes ahead of the critical match.
Leighton Morgan replaces Hamish Rutherford at the top of the order.
Rutherford made a name for himself in the twenty/20 tournament last year but has failed to make much of a dent on the one-day competition this summer, scoring 49 runs in four innings.
Morgan has done reasonably well for Otago in the Plunket Shield, with 272 runs at 30.22, and deserved his opportunity, Otago coach Mike Hesson said.
"We need some more productivity at the top of the order. We've had four [disappointing] partnerships and we need a bit of solidity at the top," he said.
"Leighton . . . went very well against Canterbury in the four-dayer and we are pretty hopeful he will play well for us [today]."
Left-arm spinner Nick Beard comes into the 12, while pace bowlers Mat Harvie and Anthony Bullick drop out.
"History suggests Timaru [Aorangi Oval] can be a little on the slow side. So, if it looks slow on the day, we want the option to play two spinners."
Otago last played a one-dayer at the venue in January 2004.
Peter Fulton scored an unbeaten century to help Canterbury win by 30 runs.
Canterbury has also made some changes.
Strike bowler Hamish Bennett has been dropped and former Black Cap Craig McMillan has been sidelined with a calf strain.
Andrew Ellis and Brandon Hiini come into the 12, but there is no sign of Black Caps fast bowler Shane Bond.
He is still recovering from an abdominal strain and Canterbury coach Bob Carter was "not sure" when his star would return.
"I have nothing definite from the medical team and so there is no set date on his return. He is just in recovery mode at the moment."
Otago v Canterbury
Timaru, today
Otago: Leighton Morgan, Shaun Haig, Neil Broom, Craig Cumming (captain), Darren Broom, Nathan McCullum, Derek de Boorder, Ian Butler, Yasir Arafat, Neil Wagner, Warren McSkimming, Nick Beard.
Canterbury: Michael Papps, Rob Nicol, Peter Fulton, Johann Myburgh, Shanan Stewart, Chris Harris, Kruger Van Wyk, Andrew Ellis, Carl Frauenstein, Ryan Burson, Chris Martin, Brandon Hiini.
