Van Bronckhorst has made a solid start to his time as Rangers boss by helping them to book their place in the last 16 of the Europa League and beating Livingston last weekend.
Rangers are still four points clear at the top of the table but there are fears that the club could sell one or two of their key players in January due to their financial position.
However, Ferguson feels the Rangers board will have definitely assured the new manager that key players will not be sold in January, otherwise Van Bronckhorst would not have taken up the job.
The Rangers legend is expecting a couple to leave in the summer but admits that he would be surprised if the club decide to break up the squad in January.
The former Rangers captain said on Go Radio Football Show: “I don’t think Gio would have taken the job, I think he would have asked them, ‘am I going to keep the core group? These are important players for me’.
“I don’t think he would have come if there was going to be a fire sale.
“That might happen and you might see one or two go at the end of the season but I would be surprised if I see that in January.”
Rangers will travel to Easter Road on Wednesday night to take on Hibernian in a Scottish Premiership clash.
