The 26-year-old midfielder, who plays in Serbia for Red Star Belgrade, told La Red radio station in his homeland that his agent is speaking with Rovers.

"It would be nice to go to the Premier League," Castillo said.

"My ambition has always been to reach the best leagues in Europe such as English, Italian and Spanish leagues.

"We still haven't closed the deal. My agent is working on it. If the chance comes I would be delighted. If not, I will continue with Red Star.

"I am working to get into my best shape and maintain my performance no matter where I play."