It was a huge setback for the Black Stars as they surrendered the sole African Zone Group E ticket of the World Cup qualifying to Egypt on Sunday, confirming their absence from the global showpiece for the first time since 2006.
In June, Ghana got off to a flyer in Afcon qualifying by a 5-0 thrashing of Ethiopia but the recent bout of reality has, perhaps, left Appiah with an increased awareness of the risks of underrating his opponents.
"The qualifiers will not be easy because for so many years, I have kept saying that football has come off age and now, there is no country you can underrate," Appiah told pressmen.
"All the countries are doing so well in football and for that reason, it's very important we get a formidable squad, and when I say a formidable squad, it means more variety of players to pick from.
"Typical example was before our game against Uganda, where we had five injuries from the team that we selected and in this situation if I didn't know the crop of players to pick from, then the whole nation would have been in problems.
"For that reason, we're going to tackle each game as it comes but we'll make sure we always parade a very strong team to get a win in the subsequent games in the qualifiers."
In the World Cup qualifiers, Ghana shockingly settled for home draws with the likes of Uganda and Congo, which led to their inability to reach Russia 2018.
Sierra Leone and Kenya are the other two Group F members of Afcon 2019 qualifying.
The Black Stars return to action in March next year with an away trip to the latter.