Huddersfield Town boss David Wagner laughed off Sheffield Wednesday substitute Ross Wallace’s cheeky spying mission during Sunday’s derby defeat by Sheffield Wednesday.

But he says he will warn frontman Elias Kachunga to keep any future notes on tactical tweaks firmly in his grasp.

Watch video as David Wagner looks ahead to Preston match:

Video thumbnail, WATCH: David Wagner reflects on the defeat to Sheffield Wednesday and looks ahead to Preston
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Wallace and Town’s Michael Hefele were both brought on after 84 minutes of a John Smith’s Stadium showdown which Wednesday won through Fernando Forestieri’s 67th-minute penalty.

As Hefele handed a sheet of paper detailing head coach Wagner’s new approach to teammate Kachunga, Wallace snatched it and had a quick peek.

“I have to say I saw the funny side of it,” said Wagner ahead of his side’s Wednesday-night game at Preston North End.

“But I will tell Elias and all our players to make sure any future notes are fully protected!

“We have found previously that sometimes when you change a system a little, it helps if players see it on paper.

“Sometimes words cannot be heard properly in a noisy stadium.”