The central midfielder is a key figure for the Saints.
He came off on a stretcher against Tottenham during their FA Cup replay.
But since there was a midseason break, the 25-year-old is fully recovered from the nasty cut he had on his leg during that match.
Hasenhuttl updated the press on the return of Ward-Prowse and other injury doubts.
He said: "Today was his first day out on the pitch and we tried to keep him out there for as long as possible.
"Players always like to come back on the pitch and he has handled it well, but we must pay attention to make sure the cut is not going to open again.
"I think it looks good that, hopefully, he can play at the weekend.
"We don't want it to get worse so that he is out. We must pay attention to it.
"It looks good and he is an important player for our team. We have a few more options which means he can go back to his No 6 position.
"We have Kyle [Walker-Peters] back who can play for the first time and Yan Valery is back.
"The squad is very balanced at the moment and we have two players in every position.
"This doesn't make it easy for me, but the players can see we are balanced."