The 23-year-old was handed his debut appearance with the Black Stars ahead of Richard Ofori and Lawrence Ati-Zigi and he made several incredible saves in front of familiar fans at the Baba Yara Sports Stadium.
Appiah believes Annan could become a great shot stopper if he maintains his focus, train well and heed to advice.
"I was aware of what Felix Annan can do when giving the opportunity that's why I gave him a national team call up," Appiah told Goal.
"I've watched him several times with Kotoko in the Ghana Premier League and in his first competitive game for the Black Stars, he impressed everyone. I'm very happy for him.
"All what he needed was the confidence and with what I saw he is ready to be up there. I always use myself as a point of reference because I was like him at Kotoko when I had my first call up to the Black Stars.
"That opportunity changed a lot of things in my career because I learned from top players during national team assignment.
"I believe that if he doesn't become complacent, trains well and listens to the advice, he will continue to develop and probably become a top-class goalkeeper very soon," he added.
Ghana will travel to Addis Ababa next month to face Ethiopia in the penultimate game of 2019 Africa Cup of Nations qualifiers.