Colak was snapped up by former Rangers boss Giovanni van Bronckhorst last summer, with the Gers planning for life without Alfredo Morelos.
Though Colak did score goals last term, he fell out of favour with Van Bronckhorst’s successor Michael Beale and is on the chopping block in the ongoing transfer window.
Rangers will sell Colak and are looking to recoup the £2.5m they paid to sign him from PAOK Salonika.
The Croatian has interest from Italy in the shape of Serie B side Pisa and, according to Italian outlet Calciomercato.com, they are in talks with Rangers.
Pisa are trying to find a deal which works for Rangers as they look to tempt Colak to Italy.
Colak would have to be willing to drop into the Italian second tier to make the move though.
Pisa finished in eleventh place in the Serie B standings last season and want Colak to fire them towards a promotion push next season.
