Manchester United hero Paul McGrath say he can relate to Cristiano Ronaldo's meltdown against Tottenham last week.
Writing for the Sunday World, McGrath said: "I had a chilling flashback as the lights went out on Cristiano Ronaldo's Manchester United second coming.
"And I felt the deepest pang of sympathy as I watched the world's most famous athlete grow old in front of my eyes.
"I know Cristiano has been lambasted for storming off in a huff during the Spurs game on Wednesday night.
"But you know what, I kind of understood where he was coming from.
"I have been in that dark place.
"The most terrifying point in the career of any professional footballer is the moment he is confronted by his own athletic mortality, when he can see the finishing line of the only life he has known hurtling toward him like a runaway train.
"All sorts of thoughts flood through your mind: Panic, desolation, confusion. You feel terribly alone.
"And incredibly vulnerable.
"Honestly, it was an earthshattering experience for me – and I had nothing like Ronaldo's profile.
"Now imagine how those sensations must be magnified if you are a global megastar, one of the greatest to have played the game, an individual who has rewritten the record books.
"The thought of losing all that, of no longer being able to do the stuff that set you apart from even the best of the rest, can cause you to do the most self-destructive things.
"Like refuse to go on to a pitch. Or marching off to the dressing room while your team are still fighting for three points."