Inter won the first-leg of their quarterfinal 2-1 on Tuesday night, with Lautaro Martinez and Davide Frattesi's goals sandwiching Thomas Muller's effort.
Kompany said afterwards: “We started the match well, we dominated the game in the first 30 minutes and could have scored one or two goals, maybe even more.
“Then in the second half, we were dominant, we created chances, but in the end, we know Thomas always plays an important role.
“When he came on, he found the equaliser. We prepared ourselves as best as possible for this match, and every decision was based on football reasons.
“Inter were very strong today, we were missing Musiala: with Guerreiro in his position, we wanted to find the right balance. We need every player to achieve our goals, and I think Guerreiro did a good job today, just like Muller. Many players played well, only the result wasn’t right.
“I don’t want to always talk about injuries, but we have five or six. I had these players available and made the substitutions thinking about the return leg as well. Kim had a yellow card, and that’s an aspect to consider.”
On the second-leg in Milan, Kompany was optimistic.
“I’ve said it many times before, if we need to defend, we defend,” he continued.
“Today, when we had to do it, we didn’t give much away to the opponent. We could have done better in possession, but our opponent was strong. We could have scored more early on, but this gives us hope when thinking about Milan.
“There are moments when you lose focus, and they took advantage of one.
“We lost 2-1, and I can’t change that result, but it wouldn’t be right to think that this 2-1 was due to our inability to win this match, that’s not what happened tonight. The result says Inter, we’ll see next week.”