The Saints boss knows they need more players if they are to remain competitive in the top half of the Premier League this season.
He does not want a season spent fighting relegation, and hopes the team will sign three players before the window closes.
"I know we will get players in," Hasenhuttl said.
"Now comes the moment where some good opportunities are coming up.
"Our number-one choice, it may not be so easy to get now, but there are some other alternatives coming to us, loan or permanent.
"I think we know we need one or two players minimum, maybe three."