Steve Cotterill revealed his disappointment at the sale of John Utaka and admitted: I had no idea it was happening.
The Nigerian forward, who was out of contract in the summer, joined French club Montpellier over the weekend for a fee believed to be in the region of £430,000.
But while his departure reduces the Fratton Park wage bill, it has left Cotterill’s playing resources further depleted.
Cotterill said: ‘It came out of the blue to me – absolutely.
‘I never got an inclination that it was going to happen at all.
‘From a footballing point of view, it’s a major blow because he gave us good flexibility, which I don’t have.
‘He could play on the right side, left side, up front or just off the striker.
‘From a financial point of view, it’s probably very good for the club.
‘But we have to remember that it’s Portsmouth Football Club, not Portsmouth Bank on the corner of the high street.
‘We’ve got to make sure that we have a competitive football team.’
Utaka had been a regular starter for Pompey this season.
He had shown glimpses of his undoubted ability after failing to live up to the £7m price tag when he signed in July 2007.
But Cotterill felt he had made significant progress this term.
The Blues boss said: ‘It’s amazing, really.
‘I have put a lot of personal time and energy into John this season and he ends up performing.
‘Everybody has commented about how much better he has been this season, so to lose him is a blow.
‘Then, for the first time in four years, we get an offer for him and he gets sold.’