The Brazilians booked their spot in the final with a comprehensive 4-1 aggregate win, as by Peter Shalulile, Divine Lunga and Neo Maema guided the DStv Premiership champions to a 3-0 in the second leg on Tuesday.
The Arrows coach claims it was always going to be tough after fielding team with young players.
"It's going to be like that in many of the games when we're dealing with a team with a lot of youngsters, we're expecting such things and we said, 'Ok' and today was vise-versa. We started with a team that we thought experience will put us through but we couldn't. First-half we couldn't even connect three or four passes, we couldn't even come out clearly. That's why at half-time we had to make subs," Seema told SuperSport TV.
"And I said the subs that we'll make will still be inexperienced players. And this game helping us to get another game, so that we can say the players that came in got minutes.
"And I'm happy with how the game went, especially second-half, these youngsters that came they took over from what the guys did in the first-half, even if we were struggling. But second-half was a little bit better and we broke there and even had a shot at goal.
"I think it's encouraging especially for the guys that are playing for the first time. When you're coming against the quality of Mamelodi Sundowns with their bench, you see whoever is coming from the bench also, already we could see we did not have enough arsenal.
"Even [Michael] Gumede was out of legs, he worked hard in the previous game and there was nothing we could do. [Nkosinathi] Sibisi had to come out with a cut, we'll see what's happening. But I must say the youngsters that came in changed the game for us. I think it was game of two halves.
"From the first game against SuperSport [United]l I said two more games gained, we're happy because some of the guys are playing for the first time and they need to taste this. [Sanele] Khumalo again came in and did better than the past two games he played so, [Thubelihle] Magubane came in, we still have [Saziso] Magawana.
"We're still trying to give them as much game time as we can because the league is a marathon and it's going to be a difficult one. Sunday we have a difficult one again, we have few players that have played, we'll see how it goes and hopefully the injury of Sibisi is not that bad but we'll see after a day or two when we arrive at home [in Durban]," he added.