The Lancashire captain, Mike Watkinson, will miss the match against Durham at Old Trafford with a thigh strain. Lancashire may also be without Neil Fairbrother, who suffered a calf strain on his way to a century on Friday.
Kent's reserve wicketkeeper, Simon Willis, makes his cup debut against Sussex at Hove, as Kent bid to retain their 100 per cent record in one- day cricket this season.
Sussex recall Neil Lenham to the squad after a rib injury. Lenham competes for a place in the top order with Keith Newell, who has yet to make his debut in the competition. Sussex are still without Paul Jarvis, so all- rounder John North is drafted into the squad of 13 along with the veteran off-spinner, Eddie Hemmings.
John Stephenson, the Hampshire vice-captain, is battling to be fit for the match with his old county, Essex. Stephenson missed Monday's win over the West Indies with back and knee injuries.
Darren Maddy is set to open the batting for Leicestershire against Nottinghamshire at Trent Bridge. The 20-year-old batsman is included in a squad of 12 in place of Phil Robinson.
The fast bowler, Scott Boswell, could make his first-team debut for Northamptonshire, who are already eliminated, at home to Scotland. John Hughes is ruled out with a side strain and David Capel is likely to rest ankle and shoulder injuries.
Dean Hodgson is back in the Gloucestershire side for their qualifier with Glamorgan at Swansea, while the veteran pace bowler, Kevin Cooper, will also be in the side subject to a late test.
Derbyshire will be without two key batsmen as they try to keep their slim hopes alive against Yorkshire at Chesterfield. The South African, Daryll Cullinan, is out with a broken finger and Adrian Rollins has a hamstring injury. Andrew Bairstow will again keep wicket in place of Karl Krikken, who has chicken-pox.