The encounter at Benfica's academy is on the same day as the Reds' first team face Chelsea in the FA Cup, but regardless of the personnel he has available, Lewtas insists his side will be eager to test themselves on the big stage.
Ahead of the 3pm GMT kick-off on Tuesday, read on for Lewtas' pre-match preview...
On a return to European action for the young Reds…
Everyone is excited, the staff as well as the players. The group stage was difficult to navigate through and I thought the boys did it well because it was a tough group. Obviously now there are no second chances, so it's about trying to win this tie and trying to get through to the quarter-final. There is certainly a lot of excitement around and it's an extremely prestigious competition.
On the dramatic 3-2 win in Salzburg that clinched qualification, when Liverpool came from two goals down and netted decisively in stoppage time...
I think it showed the mentality and the character of the lads individually, so give them credit, and also as a group. They [Salzburg] are a tough team to play against and we had two tough games against them, even though we managed to win the two games. When we went 2-0 down against them, I thought we actually managed that period quite well and didn't let the game get away from us. We were able to fix a few issues that we had and I thought our second half was a really strong performance. As ever, you can't really rule us out because we keep pushing and never give up. We ended up winning the tie, which was more than what we needed. It was a fantastic result in what was a real tough fixture.
LFCTV GO: Highlights from a dramatic win in Salzburg
On his selection plans with the first team in FA Cup action at Chelsea on the same day…
It's an opportunity. This competition is a fantastic competition and we want to try to do our best in every one we enter because we think it's important. But at the same time, we are all clear on why we function as an Academy and the idea is to get boys in and around the first-team squad. There will be no long faces if some of our boys miss out on the Chelsea game and if some of them do go there then the staff will be extremely proud of them and hopefully they can play some first-team football, which is fantastic. For us, it's just about the next man up. We've got a good squad of players and if one player misses out then it's an opportunity for someone else to step in and get experience to play in what will be a really good game. They can also grab that opportunity to show what they can do as well. There's no worry about the squad and who we will have from a staff point of view. If the manager puts his trust in some of the young boys to go to Chelsea and play then we'll be over the moon with that, but we'll be more than confident with the boys that we have for us on the day.
On his side needing to be at their best if they are to progress…
We are going to have to be at our best, 100 per cent. We've got to make sure we control what we are able to control, and in terms of how we perform make sure we execute the things that we want to try to do on the day and then we will see where we go. It's about us going out there and being the best version of ourselves and it's up to Benfica as well to be the best version of themselves. If they are not and we are then we've got to capitalise on that, but we'll be going there to play the best Benfica team that they can put out. We will be working hard to make sure that we are the best version of ourselves.
On facing Benfica on numerous occasions in recent years…
We've travelled over there quite a few times and played them in tournaments. Many of the boys who will be with us have played there at their academy complex, which is good I think because at least it will be a little bit familiar to them. It's a small thing but that can help. They have all been tough games but high-level games every time we've played them. We'll be expecting nothing less this time around. It's one we are certainly looking forward to and I'm sure they are the same.