Despite going into the game as favorites away from home, Villa could only manage a 0-0 draw in the first leg of the round of 16 clash.
It was a very tough match, very difficult," Emery told VillaTV.
It's always difficult playing in Europe, away as well.
They have a great atmosphere here with their supporters and we competed.
We didn't play well, we didn't control the game.
But, of course, it's a very good result.
We were planning this match, thinking to play today 90 minutes, but, of course, we knew before it was very difficult to get a result here and take advantage.
Here they are feeling strong, comfortable and confident to play trying to do something with their supporters.
And now it's Villa Park, 90 minutes at Villa Park, of course we have to be ready as well in case of extra-time or a penalty shoot-out because it's always difficult in Europe.
Here Ajax, today they showed us their wishes to win, their desire, their commitment to play everybody, very intense, and we've faced them today knowing them as well.
And, of course, knowing and taking experiences of how difficult it is to play in Europe."