The 2-1 result, which saw Yunus Musah sent off, leaves Milan in the playoffs for the next round.
“The incidents went against us, but aside from that we lacked football basics in the first half,” Conceicao told Sky Italia.
“The sport is made up of duels, both attacking and defending, of aggression. For the first 20-25 minutes we got to the final third and then tried to take an extra touch, or didn’t finish, didn’t shoot at all, these are individual errors. Mistakes can happen, but we need to do more.
“With the red card, it all got more complicated, we got our heads down and tried to get back into it. We equalised, tried to win the game and then another individual error was costly. At this level, even when teams have little to play for, they are still tough and we need to be ready.”
Conceicao also said: “That depends on the pride in each of us, where they want their careers to go. We can talk about tactics, systems, dynamics, but at times we have seen – and this is not new – we have to be much, much more aggressive in the duels and present in the match.
“I liked the second half, we tried to win it down to 10 men. We didn’t manage it, now we have to focus on the next match and try to change this environment around us. We’ve got time to do that and we must do more.”