Worcestershire will be without captain Daryl Mitchell in their County Championship first division local derby against Warwickshire at Edgbaston, which starts on Wednesday May 11.
The opening batsman suffered a side strain bowling in the Clydesdale Bank 40 defeat to Derbyshire at New Road on May 8 and Worcestershire are still trying to establish the extent of the injury.
A first scan has proved inconclusive so Mitchell has been booked in for a second scan on May 10. Initial estimates for his likely absence range from three to five weeks.
Batsman Moeen Ali will deputise as captain for Mitchell against his former county but Worcestershire have yet to decide who will replace their captain at the top of the order.
Meanwhile Warwickshire will give fitness tests to their captain Jim Troughton and wicketkeeper Tim Ambrose before they finalise their side.
Troughton missed the Championship defeat by Lancashire and the 18-run CB40 defeat by Northamptonshire at Wantage Road after he suffered a bruised shoulder attempting to take a catch in last week’s CB40 win over Scotland.
Ambrose missed the Northamptonshire defeat with a bruised thumb which he suffered taking a delivery from Boyd Rankin in the Championship match against Lancashire.
Warwickshire are likely to add Darren Maddy to their squad for a possible first Championship appearance in four weeks.
Maddy has spent most of his season to date driving to and from Durham, having played in the friendly against Durham MCCU, been an unused member of the squad for the County Championship match against Durham and captained the Second XI against a strong Durham side including Steve Harmison and Phil Mustard at Longhirst Hall near Morpeth last week.