The Saints were hoping to announce the appointment of Jesse Marsch as their new manager following positive talks with the American.
But the negotiations broke down over the length of the proposed contract and Marsch will not be the new Southampton manager.
They will continue their search for a new manager but they are not keen to rush into making an appointment.
And it has been claimed that they have a serious amount of faith in the abilities of interim boss Selles.
The 39-year-old Spaniard was roped in as the assistant manager to Ralph Hasenhuttl last summer and was part of Nathan Jones’ backroom team as well.
He is now in charge of first-team training as Southampton look to bring in a new manager.
And the Spaniard will take charge of their visit to Stamford Bridge this Saturday to take on Chelsea.
Selles enjoys the confidence of the Southampton board and will remain in situ as long as the club do not bring in a new boss.
