The Gunners have struggled outside of the Emirates Stadium under Emery, with their poor away form continuing into the new season.
Speaking about their difficult 2-2 draw with Watford, where they lead 2-0 at half time, Emery said to the club's official website: "We have some young players, they need to have experiences like today.
"And also, I say to Matteo, Matteo is a very good player, he is improving, he is young, he is very emotional, he has personality and sometimes needs to make some mistakes to improve.
"In the first half he made a mistake and didn't score. In the second half we continued trying because we need to do that work and that is my responsibility because also when we can change and have a second plan - it's doing long balls and the second action - they were very strong and we didn't earn balls in that planning also.
"The key was to impose and we are going to work for have and make better our build up with the goalkeeper, with the defenders and the midfielders and also, being well when we are doing long balls for breaking their lines with long ball for taking more chances.
"Because we tried and we didn't have also chances with that second plan."