It's a pitfall that has caught out many a footballer since fans were shut out of matches nearly a full year ago.
With the background din of the supporters long removed now, every word uttered by a player is liable to be picked by a strategically placed pitchside microphone.
And Kieran Tierney was the latest as he was recorded branding a Benfica player a "diving c***" in Arsenal's Europa League clash.
Following a 1-1 draw in the first leg, the Gunners fought back as they went 2-1 down in the return match, which was actually held at Olympiacos' Karaiskakis Stadium in Piraeus, Greece.
Tierney got his side level but they still trailed on away goals before Pierre Emerick-Aubameyang was the hero with three minutes to play.
But before the Gabonese striker's heroic winner, tensions were running high - prompting the X-rated blast from the former Celtic man aimed at forward Darwin Nunez.
The Uruguayan - who scored against Rangers in the group stage of the competition - felt contact and fell to the ground under Tierney's challenge.
But the left-back appeared to remark: "You're a f****** diving c***, man."
Arsenal will be back at the ground before long as their reward for progressing to the last 16 was a tie against Olympiacos.
