The Midlands club are set to take on Bologna on Tuesday night as they look to consolidate their group stage position.
With two wins in the competition so far, Villa could take a big step towards the next phase.
He told reporters: "It is a challenge, every day and every match we are playing. We started after the break, it was very important, winning at Fulham, because the last two matches we played before - against Ipswich Town and Manchester United - we drew, and that’s not enough for us.
"We have started very well and, on the other side, we played very well before the break in the Champions League. We won two matches, but to get the balance is the most important.
"After the victory we did in Fulham, tomorrow is really a new challenge to try to keep the same mentality, the same performance, the same preparation for the match. It will be very difficult, but this is the challenge."
On having more of his squad fit, he added: "Very important. We can have more options in the starting 11 with the players. They are fit, they are getting good performances with the team.
"In this moment, we have to be intelligent and have good preparation with everyone, to try and help us on the field. I have to be clinical myself, and ask the players how we can get to being consistent physically, with the energy, playing a lot of matches in the level we are.
"Our mentality is to keep the same level we had last year in the Premier League, and the same level we can have this year in the Champions League. We had it last year in the Conference League, but of course, Champions League is more demanding than the Conference.
"Now, I am very proud of the work we are doing, but each day, even today in our training session, it is very important how they are responding, the players."