Pompey are waiting for the extent of Matt Clarke’s injury to become clear.
The former Ipswich Town centre-back limped out of Saturday’s pre-season friendly at the Hawks with a groin problem. Clarke forged a formidable partnership with Christian Burgess at the heart of Pompey’s defence last season.
And new Blues boss Kenny Jackett is hoping the problem is not too serious.
He said: ‘It’s a groin injury with Matt.
‘We can’t tell what it’s like yet but he definitely felt something go in the first 10 minutes.’
With new signing Nathan Thompson also sidelined at present, it leaves Burgess, Tom Davies and Jack Whatmough as the club’s three fit central defenders.