Never smile, unless it’s over the spilt blood of your enemy, says former Manchester United captain Roy Keane.

After watching a clip of Chelsea players larking about in the warm-up to their FA Cup replay at Birmingham City – flicking each other’s buttocks with wet towels, offering handshakes concealing an electric buzzer, that sort of thing – Keane grimaced and crushed a glass of water with his bare hand.

He snarled: “Look at that. What a carry-on. They’ve just got Andre Villas-Boas the sack with their performances, and now here they are, days later, with their heads not bowed in sombre reflection.

“If I was their manager, I’d f***ing hit them, hard, then stand over them and say, ‘Take that, you c***s, and don’t ever fanny about in the warm-up of an FA Cup 5th round replay just days after your Portuguese manager got the boot…er, again.’

“If any of them tried to have a go back, I’d snap their leg in half with my foot. An eye for an eye. Oh yeah, and I’d gouge out their eyes.

“Smite your enemies, drink their blood, laugh maniacally. That’s how we used to do it in my day.”

He added: “What the f*** are you looking at, you gawping c***s?”

Here is an edited version of Keane’s rant (sadly, none of the above quotes made the cut)…