Lavia has made a promising start to life on the South Coast following his permanent transfer from Manchester City, starting in each of their opening five league matches.
The 18-year-old scored his first goal for the Saints in the 2-1 win over Chelsea last month, but he was forced off with a hamstring injury in the same game and subsequently missed the 1-0 defeat to Wolverhampton Wanderers.
Lavia is now set for up to five weeks on the sidelines, while Livramento has begin individual training after five months out with an ACL injury.
The 19-year-old has not played for Southampton since he was stretchered off against Brighton & Hove Albion back in April of last season.
Hasenhuttl is preparing his side for their first game in 13 days after last weekend’s fixture with Brentford was postponed following the death of Queen Elizabeth II.
Speaking to reporters on Thursday, the Austrian boss believes his squad have enjoyed a productive week of training and have worked hard on various different aspects of their game ahead of Friday’s trip to Villa Park.
“So far we had everybody in the training apart from Livramento and Romeo, they are still out. The rest are training with the team,” Hasenhuttl told Southampton’s official website.
“I think we had a good week with using the time after the last game. It was a little bit strange because we prepared for an opponent, then we prepared for the next opponent without seeing if it worked or not.
“We can use a few things, in set-pieces and in open game, for this game. This was the challenge in the last days, and we had good sessions with a team that is really working hard, and hopefully we are prepared for tomorrow.”
When questioned about Lavia’s condition, Hasenuttl added: “It’s tough for him, you can see it’s not easy, because it feels like a full break after a very, very good start.
“This setback is always a chance – especially for players who are coming in here – to scan your body, scan your deficits you have, and work on this in this time you are out now. This is always the chance.
“I often speak it, a lot of players using this time for coming back even stronger, physically especially.
“He has shown he can play good football, I think he has shown this in the five games he was playing, but now he has to adapt his body to get better prepared for this tough league. This is a good chance for him and I’m sure he will grab it.”
When asked about Livramento and his return to training, Hasenhuttl said: “It looks good. Without being too euphoric I think we are on a good time schedule with him and a return to the team, so everything looks quite good at the moment.”
Hasenhuttl handed debuts to Sam Edozie and Ainsley Maitland-Niles last time out and both players will be pushing to start on Friday, while fellow deadline-day arrival Duje Caleta-Car could be in contention to make his first appearance for Southampton after missing the defeat at Wolves due to fitness issues.
The Saints currently sit 12th in the Premier League table with seven points from their opening six matches, three points ahead of Aston Villa in 17th place.
Meanwhile, 20-year-old centre-back Armel Bella-Kotchap has received his first international call-up by Germany for the upcoming international break, and he could feature against England in the Nations League on September 26.