The west Londoners have been frustrated in their attempts to bring in new blood so far as they look to build for their return to the Barclays Premier League.
Warnock admitted on Monday he had been irritated by the lack of transfer activity but he remains hopeful of bringing in new faces, which could include Hull midfielder Bullard.
"You are bound to be frustrated. We need five or six players," he told Sky Sports News.
"We have done a lot of work, but unfortunately not been able to tie anybody up
"We have got a number of targets and I'm still optimistic that I can bring enough good players in to help us in the coming season. We are working hard to get value for money and I am trying to get players in on our wage structure which we have implemented for the Premier League.
"We have been linked with a lot of players. I have spoken to three or four personally, but we haven't been able to afford either the transfer fees or the wages.
"We are down the line with a couple. Jimmy Bullard is one of a number we are talking about.
"We need strikers and centre-halves. We need a number of positions filling.
"We would like to bring three or four good players in and I'm sure we will in the next few weeks."