Sheffield United boss Danny Wilson, the Blades' fourth manager in nine months following Micky Adams' sacking in May, has signed Jean-Francois Lescinal (Swindon), Danny Philliskirk (Chelsea), Chris Porter (Derby) and Ryan Flynn (Falkirk) so far.
But Wilson told BBC Radio Sheffield: "We're desperate to bring players in, it's quite a difficult scenario because we don't know where are at the moment in terms of which players are going to be available to us.
"We have to get the wage bill down, any organisation that suffers a blow like we did last season has to take steps.
"We are reliant on other clubs coming to us. It wouldn't surprise me if people come to us at the 11th hour but I also hope we can be proactive and bring players in. The end of the transfer window cannot come quickly enough for me."