Pompey are casting their eye over keeper Arran Lee-Barrett and midfielder Gavin Mahon as Guy Whittingham seeks to shake up his squad after the York debacle.
The free agents today trained with the Blues, along with Therry Racon, as Whittingham mulls over bolstering his side in light of injury and loss of form to current regulars.
Lee-Barrett, 29, was most recently at Millwall in April as emergency cover, having previously played for Hartlepool and Ipswich, and has been without a club since the summer.
Former Watford defensive midfielder Mahon, aged 36, was with Notts County last season, although finished the campaign on loan at Stevenage.
There, he made nine appearances before his release in the summer.
Racon has been without a club after making 16 appearances for Pompey last season while on loan from Millwall.