Rangers have been told they will have to pay around £3m to Aston Villa if they are to re-sign Spanish central defender Carlos Cuellar.
The Scottish champions are believed to have offered around £1.5m for the player, who joined Villa from Rangers for £7.8m in 2008.
Rangers owner Craig Whyte this week confirmed that the Glasgow club had made a move for the 29-year-old.
But he added that keeper Allan McGregor would not be offered in exchange.
Whyte stated that the Scotland goalkeeper was not for sale, despite former national boss Alex McLeish being interested in the player he worked with at Ibrox.
"I've said that Allan is not for sale," the Rangers owner said. "We have not been approached by anybody about him.
"We've made a bid for Cuellar. But, with their managerial change, it has slowed there a bit."
Cuellar made only 16 appearances for the English top-flight outfit last season.
The Madrid-born defender joined Rangers from Osasuna in 2007 but after one season left for Villa Park as the Scottish Football Writers' Player of the Year.
He had turned down Rangers' offer of a new contract and higher wages to play in the Premier League in England but left the door open to a possible return.
"The Rangers supporters have been fantastic to me, but I am young and I want to play at the highest level and I hope they will always welcome me back," he had said.
"I want to thank them for everything."
Last week, former Rangers and Scotland boss McLeish was appointed Villa manager and has been linked with a move for McGregor, currently Scotland's first-choice goalkeeper.