Wrexham's attempts to complete a club-record transfer on deadline day fell through when the window shut before they could finish the deal.
The League Two club, owned by Hollywood stars Ryan Reynolds and Rob McElhenney, had agreed terms to sign Luke Armstrong, 27, from Harrogate Town.
Harrogate even announced that the striker had joined Wrexham for an undisclosed fee.
Wrexham said they had sent the relevant paperwork to the English Football League to complete the transfer but it was not finalised before the 11 p.m. BST deadline and Armstrong ended up staying with Harrogate.
A statement released by the Welsh club on Saturday said: "The required documentation and clearance requests could not be completed in time and Armstrong's registration has been rejected.
"The club would like to thank the player for choosing to join Wrexham earlier in the day and are disappointed that this cannot now happen (pending any appeal)."
Armstrong, who scored 16 goals for Harrogate last season and has 31 in 106 for the club overall, would have joined Wrexham as a replacement for Paul Mullin, who remains sidelined following a preseason injury against Manchester United.
Mullin suffered a punctured lung and spent time recuperating at McElhenney's Los Angeles home.