United began their Premier League campaign with a 2-1 home defeat to Brighton & Hove Albion and a crushing 4-0 surrender at Brentford, but put in a masterful display to secure a 2-1 victory over arch-rivals Liverpool on Monday.
They have also struggled to secure transfer targets in the close season, and Hasenhuttl said that United's off-field failings, combined with the challenges of adapting to a new manager's philosophy, explained their underwhelming start.
"They're a team with a new manager," Hasenhuttl told reporters ahead of Saturday's league game against United.
"And after a not very long pre-season where the new manager has to wait and every new player is coming in and not having the whole squad available to give your ideas to develop them. It is not surprising that it doesn't work immediately and everything isn't perfect.
"(But) I see a very clear identity of what they want to do now. They showed that in the last game and they showed they're a strong team. You are speaking about a top team who are going for titles and can still do that this season."
Ten Hag dropped four players, including talisman Cristiano Ronaldo and captain Harry Maguire, from the first team for their win over Liverpool.
Hasenhuttl said the Dutchman's willingness to make changes to his squad had made it "difficult" to predict United's line-up, which could also feature new signing Casemiro.
"Even if Casemiro is playing, it is not so clear in what way they'll play," Hasenhuttl added.
"We definitely are facing a strong team and in the end it is up to us to play the way we want to go.
"I think it'll be an intense game... They are strong with the ball. We can't let them get too confident."
Southampton, who are 11th in the league standings, host United on Saturday.
