Rangers are leading the chase for Portuguese youngster Tiago Pinto, according to reports.
The 21-year-old defender is currently on loan at Desportivo Trofense from Sporting Lisbon.
And his performances with Trofense are believed to have impressed Rangers' scouts, who have been checking on him in recent months.
However, Pinto has rejected a new deal an offer from Sporting to extend his current contract, which is due to expire in the summer.
Middlesbrough have also been credited with an interest in the player, who admits he will wait until the summer before considering his next move.
"I will decide my future at the end of the season," said Pinto.
"I want to progress as a footballer and if a good proposition arrives from Europe I'll consider it because I'm ambitious."