The 23-year-old South American moved to Ewood Park from Newell's last January and has scored twice in 19 appearances during his time in Lancashire.
Formica has admitted wanting to return but Rovers will not allow him to leave on a temporary basis and are thought to be holding out for €5million.
"My agent spoke with the leaders of Blackburn to see if they would let me go on loan. It was a possibility and I got excited a lot," Formica previously said.
"But the sporting director told him to sit and talk only if it was a sale."
Meanwhile, Blackburn manager Steve Kean faces a fight to keep his number two Paul Clement.
Clement only joined the club three months ago but new Paris St-Germain boss Carlo Ancelotti is reportedly keen to be reunited with him in France.