Koeman, 53, has impressed since taking the Southampton job in 2014, achieving two top seven finishes in the Premier League - but the former Feyenoord boss appears to heading for the exit.
It's claimed that Koeman is leaving to take the manager's job with Premier League rivals Everton, leaving Southampton to try and find another manager, two years after losing Mauricio Pochettino to Tottenham.
A number of managers should be interested in the job given how Pochettino and Koeman grew on the South Coast, and a host of names are already being linked.
The Telegraph report that whilst Bournemouth's Eddie Howe is a target, Sevilla manager Unai Emery is also under consideration for the job at St. Mary's Stadium.
The Spaniard, 44, has become a record-breaking manager having won three Europa League titles in a row with Sevilla, and it now seems that he could be heading to England.
It's stated that Emery has been considered for the Southampton job before, and he's keen on the move as he wants to manage in the Premier League.
Landing Emery to replace Koeman would be quite the coup for Southampton, and it's somewhat ironic that Everton held talks with Emery before choosing to go for Koeman in the last few days.