This after his side conceded two goals from set-pieces against Orlando Pirates in their 4-1 defeat in the Telkom Knockout quarterfinal at Orlando Stadium on Saturday night.
This was the second time that they conceded from a set-piece, after they did the same against Kaizer Chiefs in a league encounter, which they lost 1-0.
“It is a concern obviously, but I think we have to keep reminding ourselves that we’ve got an 18-year-old and a 20-year-old as our two centre backs,” reasoned De Sa.
“We will get mistakes like that and lapses [in concentration. They will come against big, strong guys and they will learn from it, that's all.
“I know we conceded against Chiefs like that, but it is slightly different from the two we conceded against Pirates. It was just maybe inexperience and something that we have to pick up when we watch the videos, and hopefully they don't do it again.”
With seven of their starting eleven under the age of 21, De Sa believes that his side will be a good team in future, if they can stick together for a while.
“We don't look at their ages, it just happened that way that we played a young team. We just pick the best we have, and those players are the best we have.
“They have been playing the majority of the games and they have been doing pretty well. I think they will get better and games like this are ones they are going to learn from.
“If we can keep the side together, I think they will be a good team,” concluded the former Pirates coach.