Noe Pamarot grabbed Pompey's other two goals and Redknapp told Sky Sports News: "Sometimes when you need to raise money to buy a player you have to sell another one you don't want to sell.
"It could be David but then again it could be anyone. We need a striker capable of scoring 15 goals a season and if the chance comes to improve the team before transfer deadline (Friday) we'll do it."
Assistant manager Joe Jordan said he was pleased for Nugent to get off the mark for the club.
He said: "I think that (speculation) has been an extra burden to him and I think that once the transfer deadline is over then he can get on with it and realise where his future is.
"There is so much speculation going on but only some of it is true and I'm talking about players in general. You can't avoid it. It comes with the territory, but with David I just don't know.
On the match, Jordan admitted: "It was a satisfactory performance but 3-0 flattered us and Leeds deserved some credit out of the game. The result was a little hard on them."