Former Durham batsman Jon Lewis will take charge of the Dynamos in the absence of Geoff Cook when Hampshire Royals make the trip north for a potentially pivotal Yorkshire Bank 40 fixture.
Cook suffered a heart attack on Wednesday and remains in a critical but stable condition in hospital.
Second XI coach Lewis takes over the 61-year-old’s duties as head coach in the interim, with veteran batsman Dale Benkenstein set to offer assistance once their Friends Life t20 campaign starts next Friday.
A win would see Durham, who have won three YB40 matches in succession, replace unbeaten Hampshire at the top of Group B, although the current leaders have played one fewer game.
Left-arm seamer Jamie Harrison could be handed his maiden first-team outing of the summer for the Dynamos as Mark Wood is absent with illness.
Michael Richardson has also been added to Durham’s squad, while Hampshire are unchanged from their victory over Derbyshire earlier in the week.
Nottinghamshire and Sussex, two teams in YB40 action today, begin an LV= County Championship fixture at Trent Bridge tomorrow.
Sussex, who boast the only unbeaten record in Division One, currently lie third, while Notts are 27 points further back with a game in hand.