Due to Financial Fair Play regulations, the Blades are dealing with a strict transfer budget in the ongoing window.
However, Sheffield United have seen an exodus of key players from Bramall Lane in the form of Sander Berge, Iliman Ndiaye and Billy Sharp.
The Blades have dipped into the market and have recruited five players in the ongoing transfer window.
And it is said that they have agreed a deal with Coventry City for midfielder Hamer for a transfer fee worth £15m.
Hamer is set to undergo a medical today with the Bramall Lane outfit before he completes his signing for the Blades.
Paul Heckingbottom does not want to stop with the capture of Hamer though and more are wanted in through the door.
Sheffield United will stay active in the market in the hope of strengthening their squad with further signings.
The Blades will welcome Crystal Palace on Saturday at Bramall Lane to begin their Premier League campaign.
