Former Republic of Ireland goalkeeper Dean Kiely is expected to miss the start of the new season through injury.
Kiely, who was last season's number one keeper for Pompey, ruptured a thigh muscle in Thursday's friendly against Porto at Fratton Park and could be out for three weeks.
The news leaves Portsmouth with a goalkeeping crisis ahead of Saturday's Premiership kick-off despite recently signing David James from Manchester City.
Third-choice Jamie Ashdown is already out until mid-September after breaking a thumb and untried youngster Nick Jordan is the only other option for the substitutes' bench unless manager Harry Redknapp signs another keeper on loan.
At least the injury saves manager Harry Redknapp a run-in with Kiely who starred in the great escape from relegation after being signed from Charlton for £500,000 in January.
James sealed a two-year deal at Fratton Park on Friday, making him Pompey's fourth summer signing of the summer but Redknapp had insisted it would still be a fight between James, Kiely and Ashdown for the starting role.
Redknapp rates James, 36, as "still one of the best in the business and can stay at the top of the game for years to come".
And the former England, West Ham, Aston Villa, Liverpool and Watford star, signed from Manchester City, has already been pictured with the Pompey number one jersey.
Kiely, just a few months younger than James, had warned he intends to fight for his place in the side, saying: "I would think it an injustice if I was replaced in the side considering my contribution last season."
He recently quashed fears that he had broken a finger in pre-season training for a second year in a row — only to subsequently suffer the thigh injury.
Redknapp confirmed: "We are delighted to get James. Dean Kiely and Jamie Ashdown are injured. So we needed to get him."
Meanwhile, talks aimed at landing striker Kanu on a one-year deal at Pompey are continuing even though Valencia and Hamburg are also interested in the player.
Kanu, 30, has reportedly stated a preference to remain in England after spells with Arsenal and West Brom.
And Redknapp could also pursue his interest in Aston Villa midfielder Gareth Barry despite a £4.5million bid being rejected earlier this month.
