The Saints were relegated from the Premier League last season and now they are going through a squad overhaul.
They shipped 73 goals in the previous campaign and central defender Caleta-Car is being heavily linked with French club Lyon for a move away.
It has been suggested that the Saints have held talks with Everton regarding Holgate in recent weeks as they are looking to bring in a replacement for the Croatian.
Now the Southampton boss has given his green signal to go for the English defender this summer.
It has also been claimed that the Merseyside outfit are open to letting Holgate leave this summer either on loan or on a permanent deal.
The versatile defender barely featured for the Toffees in the previous campaign as he registered only nine appearances in all competitions in the process.
Newly promoted Premier League outfit Sheffield United were also interested in Holgate earlier in the transfer window.
