The Ibrox club have been linked with a move for the 22-year-old, who has enjoyed a stand-out season in Belgian football.
They have been warned off making a move for former Hearts defender James Penrice, with AEK Athens insisting he is too important a player for their title charge in Greece for them to consider selling him.
Charai was assistant manager at Rangers under Philippe Clement and remained at the club until this summer before he took charge of Westerlo.
They are currently on a training camp in Turkey during the Belgian winter break and Charai was quizzed about Rangers’ reported interest in Rommens.
He said: “There has been no official bid for Tuur Rommens.
“And our situation at left back has been well documented. We need reinforcements in that position.
“As a manager, you always want more new signings to add to the squad and that is our priority this window.
“The hope is to improve the players we already have. We still have ten league matches and then the play-offs to make this a memorable season.”
Former Belgium Under 21s skipper Rommens is rated at around £3.5 million.