With Titus Bramble also having recently departed, there is space on the payroll for a signifcant signing and Stam is said to be Martinez' number one choice.
The 26 year old is predominantly right footed but can play at either full back position, adding fuel to speculation that Maynor Figueroa is set to complete his move to Liverpool.
A fee of £2 million is being touted for the defender who has also been linked with Ajax and played a big part in Twente's title winning success last term.