The Republic of Ireland were knocked out of Euro 2016 on Sunday.
Zola is still widely regarded as one of the Premier League's most successful foreign players ever, but fears Brexit may cause others to stay away.
The 19-year-old defender was released by Villa at the end of last season.
The experienced stopper is the latest arrival at Ibrox.
Tottenham Hotspur attacker Heung-Min Son only made 13 Premier League starts in his first season at White Hart Lane.
West Ham United teammates Darren Randolph and Dimitri Payet came up against each other in the Republic of Ireland's match against France.
The France manager has offered his backing to the Arsenal defender.
Sunderland target Neven Subotic has confirmed he will be leaving Borussia Dortmund.
Miguel Llera has tipped former side Sheffield Wednesday for promotion next season.
HITC Sport understands a host of Premier League clubs are tracking Euro 2016 hero.