Harry Redknapp has admitted he is prepared to sell £6million summer signing David Nugent if it means he can bring another striker to Fratton Park.
Nugent has been with the South Coast club for less than two months after his move from Preston in July.
The former England Under 21 international scored his first goal for the club in the 3-0 Carling Cup victory over Leeds, but after the match Redknapp made it clear Nugent's brief stay could end before Friday's transfer deadline.
Derby looks the most likely destination for Nugent where he would link up again with his former Preston boss Billy Davies.
Redknapp told Sky Sports News: "You are always looking to improve your team and it just depends who was available. If someone came up who was a fantastic option and I had to sell somebody, it's whoever you can sell.
"You need to raise money sometimes, you have to sell people that you're not so keen to sell because you want to get somebody else in.
"It's no secret Derby would like to buy him (Nugent). His old manager fancies him at Derby, we'll have to wait and see.
"Derby have been in and they would like to sign him, they would like him very much. Billy knows him and if David wants to go... if people want to move then you let them go.
"It's up to David really, I'll have a chat with him and see what his plans are."
Redknapp confirmed any new additions to his forward line would be big-name players, but moved to play down reports Bolton forward Nicolas Anelka could be coming to Pompey.
He said: "We are looking, we are trying, and if I do bring one in it would be a good one, that's for sure, it won't be just anyone.
"I doubt if it would be Anelka. I like Anelka, but I doubt that very much.
"You need someone in your side who can get you 15 to 20 goals a season, and if you can find somebody like that they're like gold dust. There's only a certain amount of people capable of doing that around.
"I might have to sacrifice one or two players who people think are good players because I want to improve the team.
"It's not a case of if it's David or someone else. If I have to raise some money to buy a top player, it's who you get an offer for.
"If someone makes an offer you think 'OK, I'll have to do that, because I want to get this player in,' and that's how the business works."