Liverpool will be back in domestic action on Saturday afternoon when they make the trip to the south coast to face the Saints at St Mary's Stadium.
Hasenhuttl, though, believes Jurgen Klopp's squad will be more than ready to return to domestic duties and build on their opening 4-1 victory over Norwich City.
"This team has so much quality, and Jurgen tries to puts out maybe a little bit of an excuse for the fitness from his players," Hasenhuttl said.
"But he doesn't have to, they have such quality, it is not a problem for them after 120 minutes on the Wednesday to come here and make a good game.
"In modern football and especially with these big teams, they get used to it. We are at the beginning of the season and that does not really mean they are tired.
"I expect the best best possible Liverpool team you can imagine, and we are preparing for this."
Southampton got their Premier League campaign off to a disappointing start when they suffered a 3-0 defeat at the hands of Burnley at Turf Moor.
A brace from Ashley Barnes and a goal from Johann Berg Gudmundsson was the difference on the opening weekend in Lancashire and now Saints are up against it when Premier League title contenders Liverpool come to town this weekend.
Summer signing Che Adams impressed at times during his top-flight debut last weekend and Hasenhuttl will be hoping the former Birmingham City striker can open his account against the Merseysiders.
Hasenhuttl was nicknamed the 'Klopp of the Alps' during his tenure at previous club RB Leipzig and the Austrian will be looking to mastermind what would be one of the upsets of the weekend, if they can take points off the European champions.
Saints will have to sure up what has been a leaky defence in their recent meetings with the prolific Liverpool attack.
The Reds have scored 11 goals in their previous four Premier League meetings with Southampton, in a fixture that Liverpool striker Mohamed Salah has scored in in every match he has played against the south-coast outfit.