Frank Lampard admits he was surprised by Marcelo Bielsa's "incredible" hour-long presentation detailing his research into opposition.
Bielsa also revealed he had spied on training sessions of every team Leeds have played this season after a member of his staff was found at Derby's training ground last week and removed by police.
Lampard admitted he had not seen the news conference himself, but appeared bemused by Bielsa's behaviour.
"I was surprised definitely, it was incredible," said Lampard, after his Derby side beat Southampton on penalties to progress to the fourth round of the FA Cup.
Asked if Bielsa gave the impression he knew more about Derby, Lampard said: "He gave an impression. I haven't seen Pep Guardiola give that impression, Jurgen Klopp give that, Mauricio Pochettino give that. They do it behind closed doors definitely, but they don't do it to the public.
"Yeah [everyone does research] it's really simple. It's probably a nice eye-opener for the fan to see it because most of this stuff happens behind closed doors.
"But they are done everywhere, there's no amazement from anyone who works in football.
"It is what it is now, we all know what's been happening across the board. It's certainly a league issue now because it is our league it's every team. So it's up to them to decide what goes from now."