Chesterfield will not make a second bid for Mansfield midfielder Sam Clucas, according to Sky sources.
Ronald Koeman admits it is unlikely Southampton will be able to sign winger Andros Townsend from Tottenham before Monday.
The Seagulls brought in Leroy Lita on loan from Swansea last week but are still looking to strengthen further and have been linked with Nottingham Forest's Dexter Blackstock.
They are currently without Leonardo Ulloa, Craig Mackail-Smith and Will Hoskins due to injury and drew another blank in Saturday's goalless draw at Yeovil.
It was the third time in seven outings that Albion had played out a goalless draw.
Assistant boss Nathan Jones said: "It's been very frustrating because we know exactly what we need.
"Obviously we don't want to bring in just anyone, we want players that can affect our squad and make us better.
"We have identified the type of player we want but it has proved a little more difficult than we thought to bring in.
"We can't count our chickens before they hatch; it's the old cliche, but we are working hard to try and put that right and get more competition for front places, and to bring in someone with a bit of a record who's going to lift us."