Here, Press Association Sport takes a look at some of the key issues for the Austrian to address when he walks into his office at St Mary's Stadium.
Build from the back
An old cliche, but one which nevertheless would serve the 51-year-old well, or indeed any other new coach. Had Hughes' side been able to hold onto their 2-0 lead over Manchester United on Saturday, then he most probably would still have been in a job. Hasenhuttl should get a good view of what work needs to be done when taking in Wednesday's Premier League match against Tottenham at Wembley.
Get the home fans on side – quickly
Southampton' failure to hold out against United means the wait goes on for a first home Premier League win, with five draws and two defeats so far. The first opportunity for Hasenhuttl to ingratiate himself with the Saints faithful comes on December 16 with the visit of Arsenal. No-one said this was going to be easy...
Settle on a system
Hughes had experimented with three at the back in recent fixtures, which worked well despite a penalty shoot-out defeat to Leicester in the Carabao Cup, but not so when 3-4-3 left them overrun by United's recovery. Southampton have the personnel to be versatile, but need to get the right balance at both ends as a priority.
Pick your battles
Getting anything out of United, whatever indifferent form they may be in at the time, is always a bonus, so in isolation a draw could be viewed as a positive result. The upcoming games, though, do not get any more unforgiving with a trip to Wembley against a Spurs side out to make a point following their north-London derby defeat. Hasenhuttl is set to be in full control for the away game at Cardiff for a fixture against one of their direct relegation rivals which should be targeted for maximum returns along with the visit to Huddersfield before Christmas.
Buckle up, this could get bumpy
Former Unterhaching and RB Leipzig coach Hasenhuttl brings with him a reputation for giving youngsters a chance and a progressive playing style, with the emphasis on hard work and fitness. However, the hustle and bustle of an unforgiving and relentless English top flight is like nothing the Austrian will have experienced first hand before. Time is a luxury he simply will not have, so needs to hit the ground running – or face the consequences.