Rangers have given up on luring former defender Carlos Cuellar back to Ibrox from Aston Villa.
The clubs agreed a fee of around £2m for the 29-year-old but concerns over the Spaniard's fitness have derailed the proposed transfer.
"We will not be making a move for him before the transfer window closes," director of football Gordon Smith told BBC Radio Scotland.
"The problem was we were waiting to see what his injury situation was."
The central defender, who moved to Villa from Ibrox for £7.8m in 2008, is currently recovering from a knee injury and is not included in Alex McLeish's squad for Saturday's trip to Fulham.
On Friday, Rangers boss Ally McCoist said there were "one or two issues" surrounding the deal for Cuellar.
"His injury is coming along fine, there is no problem with that. It's just the fact that he's not ready to play right now that would be a definite problem for us."
"He has been here before and he was terrific for us."
McCoist may now turn his attention to a loan return for Liverpool's Danny Wilson.
The 19-year-old switched to Liverpool from Rangers in a £2m transfer in July 2010 but has featured only eight times for the English Premier League club.
Wilson was quoted this week as saying he would consider a loan to win first-team football,
And McCoist said: "Danny is a player we know very well, he is a great talent and will only get better."
McCoist has missed out on a number of signing targets, including David Goodwillie, Kenny Miller, Craig Conway and Neil Danns.
And the Ibrox boss appears resigned to losing out in his pursuit of another option in central defence, Anderlecht's Roland Juhasz.
Rangers bid £3m for the Hungary international, but the Belgian club are demanding £500,000 more for the 28-year-old.
"If they're saying the deal is dead then I would probably say the deal is dead," McCoist said of the prolonged negotiations with Anderlecht.
Smith insisted McCoist was getting the full backing of the Rangers board and said that more signings would be made before the end of August.
"You have to be sensible," said Smith. "Football is also a business and it has been an ailing business for a few years now.
"But Ally McCoist has never hinted that he's not getting the support of the board or the owner.
"We've kept important players at the club on long-term deals and, if Matt Mckay and Alejandro Bedoya sign, that will be six new players.
"Tell me another club that has done 12 deals during the summer in Scotland.
"Work is being done, progress is being made. We are positive about what is taking place."