Leeds United head coach Marcelo Bielsa says practising penalties can be "meaningless" due to the inability to recreate an in-game atmosphere.
The Argentine admitted that United had practised spot kicks over the course of the campaign but has seen his side miss their last three efforts from 12-yards.
Kemar Roofe was the latest Leeds player to have a mishap from the penalty spot after he saw his effort fly over the bar after losing his footing in last weekend's 3-2 defeat at Ipswich Town.
Patrick Bamford and Pablo Hernandez have also failed to convert in recent months, with penalties potentially playing a key role in United's fate over the next two weeks as they enter the Championship play-offs.
Leeds head to Derby on Saturday evening in the first leg of their semi-final clash with the Rams at Pride Park.
The return leg will take place next Wednesday at Elland Road with extra-time and penalties in play should the score remain level on aggregate over the two legs.
Bielsa, though, was asked whether he was worried over his sides inability to covert and if United had been rehearsing penalties in the build-up to the play-offs.
"To train the penalties it's good to find out," he said, "not only the coach, but also the players, to find out who is good at penalties and who is not.
"But being good at penalties doesn’t mean you’re good at penalties in front of 50,000 people.
"At the same time, being good at penalties in games is not the same as games like that. What I’m telling you is that it’s meaningless to work on penalties because you cannot reproduce both important aspects of the penalties.
"But at the same time I can tell you we shot hundreds and hundreds of penalties during the season. But at the same time we missed the last three."