The fullback is being followed by Liverpool ahead of the January market.
And it's emerged Rensch is facing a sale as talks over a new contract threaten to collapse.
Johan Inan reports for AD: “Ajax cuts and wants to get rid of the Champions League salaries that were previously thrown. (Steven) Berghuis and Rensch signed their (last) Ajax contract at that time. With that they press hard on the household. To stay they have to settle for less."
Inan writes that the proposed salary reduction is to "the extent to which players will now consider leaving.
“The temptation to do so has become much greater for the almost 22-year-old Rensch than for the almost 33-year-old Berghuis."
Rensch has been linked with several major clubs from abroad, including Liverpool, in recent months.
“As a result, he cannot only improve sports. Because clubs bid against each other, a transfer also becomes financially interesting for him.”