The Terriers travel to Sheffield Wednesday for an eagerly-awaited second leg with the tie level at 0-0.
With so few chances created at the John Smith’s Stadium on Sunday, there is a chance that Wednesday night’s return could go to extra-time or even penalties.
Asked if he had decided yet which of his players would take a spot-kick, Wagner replied: “You cannot practice penalty shoot-outs, in my opinion. This is a totally different atmosphere in the semi-finals.
“But we are pretty confident that we are able to put the ball in the net from 12 yards. We have enough Germans in our team and everyone knows Germans are able to win penalty shoot-outs!”
Town’s four-game losing run under Wagner against the Owls came to an end on Sunday.
Goalkeeper Danny Ward missed that goalless draw through suspension and was unable to train on Monday due to illness.
However, Wagner expects the Liverpool loanee to join in with his team-mates during tomorrow night’s training session and then be ready to start at Hillsborough.
The German added: “Danny is back. He was a bit ill today and unable to train. But this will not be a major issue. If he is healthy and fit, he will start.”
As for the second leg, the Terriers head coach added: “We will be prepared for everything. If extra time, we will be there. If it is a penalty shoot-out, we will be there. If it is 90 minutes, we will be there as well.
“I have no concerns about our fitness, whatever happens. If it goes to extra time, this will be more an advantage for us.”