A permanent transfer deal to sign Oscar Cortes would cost Rangers £4m.
The Colombian winger has been on loan at Ibrox for the second half of the season.
Cortes, 20, joined from RC Lens in January and had impressed before injury curtailed his impact.
However, Philippe Clement previously refused to rule out a permanent deal for Cortes after discussions with parent club Lens.
“We are talking with Lens about what the situation is because in this situation it is a different situation from when he was fit,” said Clement previously.
“At the moment he was fit he was showing the right things, but it was really short term. Then it needs to be at the right price.”
Asked about the possibility of Cortes returning to Rangers on loan next season, Clement added: “That is something to discuss. We will see what is said in the talks with Lens. I cannot say just now.”
The Rangers Review have now confirmed it would take a £4m fee to sign Cortes full-time in Glasgow.
Lens paid a similar fee for Cortes to sign him from Millonarios 12 months ago and would be looking to recoup that amount to sanction a deal to Rangers.
It's understood that Cortes has remained in Glasgow recently to use the Auchenhowie facilities to continue his return to fitness.
“I’m doing well now, after everything that has happened,” Cortes said in an interview in his homeland last month. “There were obviously difficult times but I think that with the help of all the people I have around me they helped me a lot, and they have helped me to be calm in my head as well.
"I arrived and started to do things very well and well unfortunately the injury came and I had to stop for three months but I thank God I am already in the recovery process.
“Me and my agents are keeping tabs on the negotiations that are taking place. We will see what happens. I'm talking to my agents and also to Lens and Rangers. Let's see what happens. I am waiting.
“Since I started playing soccer, my dream has been to play for Real Madrid, it has always been my dream. My dream is to get to Real Madrid. With work and sacrifice I believe that it can be achieved at some point. They are my team.”
