Sheffield United boss Kevin Blackwell has dropped his interest in the four trialists who were hoping to impress at Bramall Lane.
Strikers Henri Camara and Fabrice Pancrate were under consideration for deals with the Blades along with Elliot Omozusi and Facundo Zampa.
The quartet all featured in last week's second string outing against Sheffield Wednesday at Hillsborough.
Blackwell was keen to bolster his squad, but despite offering a deal to Camara they were unable to agree terms with the former Wolves and Wigan man.
And the Blades boss revealed his frustration at the involvement of numerous agents, which he feels contributed to the talks breaking down.
"We put a decent offer to Camara and his agent but it seems that they had to speak to various other people and it became a nightmare, a nonsensical situation," he told the club's official website.
"I spoke to another agent last week and he seemed to want more than the player he was representing - we need more money in the game but this sort of thing is spoiling the whole system.
"It seems that you can talk to a player, satisfy him about the club, the area and the contract, but then there's a line of other people in the background who start moving the goalposts.
"Sometimes there are so many of them it is hard to find out just who the agent is. One agent wanted £75,000 from us for a player to come on loan just until Christmas - and the player was out of contract!"