Hampshire will wait until as late as possible before making a decision on John Crawley ahead of the visit of Kent.
The veteran batsman missed the Pro40 game against Gloucestershire on Sunday with back spasms and is considered doubtful to recover in time.
Hampshire - still in the title hunt - add seamers David Balcombe and David Griffiths to their squad.
Kent are poised to welcome back Darren Stevens for the trip to the Rose Bowl.
Stevens has overcome a groin injury to bolster Kent in their bid to avoid relegation from Division One.
The former Leicestershire all-rounder replaces Sri Lankan paceman Lasith Malinga, who has left the county to join up with his national team at the World Twenty20.
Ryan McLaren is also set to feature with the aid of painkillers in his broken right thumb.