England’s head coach is not known for screaming and shouting, rarely raising his voice when a gentle nudge in the right direction will do.
But the Australian admitted he was concerned enough by the warm up performance against Ireland to dish out some home truths.
“We had a fairly stern chat after the game,” Bayliss said.
“It’s good to be able to deliver those messages when you have actually won a game.
“I thought the example Jack Leach showed was the example a lot of the other batters need to learn from.
“He was very focused on what he wanted to do and was very clear in his own mind how he was going to go about it.
“We speak about that a lot, having a plan for any situation you find yourself in and being clear with your thoughts, don’t try and just bluff your way through it.”
England managed to bluff their way out of humiliating defeat against Ireland despite being bowled out for 85 in their first innings, firing back with the ball to skittle the Test minnows for 38 in the second innings.
Yet Bayliss knows they will need greater intensity when they join up at Edgbaston on Monday.
England begin Ashes week with an optional training session, where the fitness of paceman Jofra Archer will be assessed following the side strain that dogged his World Cup campaign.
“We don’t want to necessarily risk him,” said Bayliss.
“He played for Sussex in a T20 match and came through that well.
“Test match cricket, five days, longer spells is a little bit of a different beast so we’ll have to see where he’s at and take a little bit from the medical people as well.
“We have to weigh up do you pick him for the first one, it’s a bit early, he gets injured and then is unavailable for selection.
“We’ve got a good strong group of bowlers who we think can do the job over the five Tests.”
The Ashes get underway at Edgbaston on Thursday, with Australia currently in possession of the urn.