On Saturday the Austrian oversaw a 1-0 defeat by fellow-strugglers Cardiff City, having had only 48 hours to prepare his side.
Now he intends to make the most of the coming days before next Sunday's Premier League game at home to Arsenal.
That fixture begins a hectic period of five league matches and an FA Cup tie in the space of three weeks, during which there will be less time available for instilling his methods.
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"It’s the most important week in the next month, because we have enough time to work on a lot of things," Hasenhuettl told the club's website.
"There are a lot of things that are not (automatic) and are not habits, which is what we want to see. We have time now, and we need to fill this time with impacts."
The Cardiff defeat meant Saints have lost seven and drawn five of their 12 league games since recording their only victory of the season, at Crystal Palace on the first day of September.
The bad run cost Mark Hughes his job last week and led to former RB Leipzig coach Hasenhuettl taking his first position in English football.
He said after his appointment that he favours a high-energy pressing game that "depends on heart and a lot of running," so the players can expect plenty of hard work ahead of a difficult programme of matches.
Southampton are kept off the bottom of the table only on goal difference and must face Manchester City and Chelsea in successive games just after Christmas.
"I think the fans know it’s a tough time and we have a lot of problems at the moment, but I hope we can pay back everything," Hasenhuettl said.
(Reporting by Steve Tongue; Editing by Toby Davis)
