The Republic of Ireland midfielder came off the bench to fire his side to a narrow Euro 2012 qualifier victory over Armenia in Yerevan on Friday night with his first senior goal for his country on his fourth appearance.
Fahey said: "It gives me great confidence. It's good to think that I am in his [Trapattoni's] thoughts anyway.
"There are other players he could have put on in front of me, so when I got the shout, I was delighted to get on.
"With the internationals, there are more games, you are involved more and your name is out there more, more people notice you.
"But this season, I will be looking to improve and try to get the best out of myself because I don't think I have shown the best of me yet."