Ronald Koeman's men reached the last eight of the League Cup, but were stunned 1-0 by third-tier Sheffield United as a golden opportunity to reach the semi-finals went begging.
Gardos was sent off in the final minute at Bramall Lane to cap a miserable outing for Southampton, who last reached a major final in the FA Cup in 2003, when they lost 1-0 to Arsenal.
Southampton's FA Cup campaign this season begins with a home clash against Championship high-flyers Ipswich, and defender Gardos is expecting another difficult encounter.
"Obviously I have never played in the FA Cup yet," he told the club's official website.
"It's a game at home and I've heard that it is going to be a full stadium, so I think it's going to be a nice game and a nice atmosphere.
"We have the experience of the Capital One Cup now, it's never easy in the cup.
"We lost against Sheffield United, it doesn’t matter that we are in the Premier League and Ipswich are in the Championship - it will be a hard game.
"Everybody was disappointed after Sheffield United. It was the worst game of the season for us.
"We didn't play good and we had a really bad result. But we have another chance in a different competition so we will hope to get as far as possible.
"Momentum is very important, a win doesn't matter in what competition, it gives you morale and confidence. Of course it is important to keep on winning."
