The experienced Dutch head coach has been in charge of seven sides throughout his managerial career, including European heavyweights Ajax.
Keizer, 49, signed a two-year deal with the Eredivisie club last summer but was sacked after just six months.
His agent, Humphrey Nijman, told the Scottish Sun: “If the club approached Mr Keizer then, yes, he would be interested in talking.”
Chairman Dave King earlier this week insisted Rangers would leave no stone unturned in their search for a manager, though refused to rule current boss Murty out of the running.
The former Development League coach would strengthen his bid significantly if he was able to lead his side to victory over Celtic in Sunday’s Scottish Cup semi-final.