The Dutch midfielder admits that the Reds maintained their composure despite going in at half time level with a team that consisted of Villa's young players due to an outbreak of coronavirus at the Midlands club.
Wijnaldum told Liverpool's club website: "We stayed calm and we stayed calm in the dressing room.
"We said we shouldn’t go crazy and shouldn’t lose confidence because for the first half an hour we did quite well and created chances but we didn’t score them.
"After that the counter-press was not that good so I think it was a deserved goal from them because we didn’t defend it well.
"That’s what you get in football, because when you don’t defend well then the other team, especially with their quality, can create chances and that’s what happened and they scored a goal.
"There’s a lot of things that can happen against any team so that’s what we said at half-time and we just changed a few things around."
Wijnaldum scored as Liverpool ran out 4-1 victors and admits that his team are keen to win the trophy this season, as they are yet to land the FA Cup under manager Jurgen Klopp.
He said: "I think we did well [against Villa] and hopefully we can do well in the next round because this is a competition we also want to win. We have won a lot but the FA Cup we haven’t won, so we want to do it."