And for the iconic English manager, who announced his retirement on Saturday, Diego Simeone and Atletico Madrid went too far against Manchester City in the Champions League on Wednesday night.
City clung onto their 1-0 aggregate lead from the first leg with a fiery goalless draw which descended into total mayhem.
Having relied on their trademark cynicism for most of the tie, Atletico sparked a mass brawl in the dying moments after Stefan Savic and Felipe targeted Phil Foden.
Seven yellow cards were brandished during ten minutes of stoppage time, including to Simeone, before the ugly scenes spilled over into the tunnel after full-time.
Savic pursued Jack Grealish after pulling his hair on the pitch and Sime Vrsaljko appeared hell-bent on fighting their entire City squad.
There's a famous clip of Warnock telling his Sheffield United players they've 'got to die to get three points', which does the rounds every Saturday morning on Twitter.
So when the 73-year-old says it's bad, you know it's bad.
Warnock told talkSPORT: "I must admit, when I watched it, the second-half - I couldn't stop watching, I was gripped.
"I kept jumping off my seat with the tackles and all the professionalism, crossing my fingers that Man City would go through.
"It was only the last 15 minutes that it really became like that and I think Atletico were their own worst enemies.
"If they kept their cool, they'd have had a lot more chance of getting that goal - but they lost it.
"We all do it, all the managers waste time, especially away from home, and referees don't add that much on - and I loved it when Simeone and all the players were talking about City time-wasting - they never even tried to play in Manchester!
"But it just goes to show how good Atletico are. I haven't seen many sides create that many chances against Man City.
"For football, it's a blessing they got knocked out. I've got a reputation, but I've never been as bad as Simeone last night. Deary me.
"I just couldn't believe it. I know you'll laugh at me, I'm the biggest critic of referees, but I thought it was unrefereeable!
"I thought the ref did brilliantly."
Atletico created a number of chances after deciding to attack City for the final 20 minutes of the match.
And Warnock believes they would give anyone a game if they stopped being so negative.
"They're so used to stopping other teams with negativity, they're the best at it in the world," Warnock added.
"But for me, the reason they do well, when they play - they're a hell of a good side!
"It's just they've got so much in their minds about stopping other players and deliberately doing this and that, they forget how good they are.
"It's their own downfall. You look at the squad they've got, when they do play, they're as good as anybody.
"They were deceitful and devious. It made me proud to be British watching City win."