Roy Keane contemplated early retirement in 2001 after a "ridiculous" moment left him questioning if he was still able to play at the top level.
The former Manchester United captain, who is widely regarded as one of the Premier League's greatest midfielders, enjoyed a trophy-laden 12-year spell at Old Trafford, where he helped Sir Alex Ferguson's side win multiple trophies.
In fact, he captained United for eight years between 1997 and 2005 before leaving to join Celtic.
After previously suggesting he would never forgive Ferguson for the part he played in his Old Trafford exit, Keane recently detailed the moments before his infamous departure and why he took "issue" with a meeting organised by his former manager and David Gill.
Keane would eventually hang up his boots in 2006, but he previously admitted that he came close to hanging up his boots five years prior to his official retirement following a heated game against Newcastle United.
The match at St James' Park, which ended in a 4-3 win for the home side, is remembered most for a flashpoint between Keane and Alan Shearer.
In the final minutes of normal time, Keane threw the ball at Shearer after going to take a throw-in – prompting the Magpies striker to push him in response. The midfielder lost his temper and went to throw a punch at Shearer, resulting in the yellow card he was about to be shown being upgraded to a red.
Speaking in 2021, Keane said the decision by referee Steve Bennett to send him off left him furious.
"I lost my temper, we were losing 4-3, I think, in the last minute," he said. "If you're going to get sent off, the worst thing is, I pushed him. If you're going to get sent off you might as well punch him properly because you're going to get the same punishment.
"You might as well be hung for a sheep as a lamb. That's what I was thinking afterwards. It was just a push. It was ridiculous."
Keane takes a swing at Newcastle captain Alan Shearer. Image credit: Getty
Keane takes a swing at Newcastle captain Alan Shearer. Image credit: Getty
Keane feared he was finished at the top level in the wake of the sending off, and even told his manager Ferguson he could retire.
"I was fed up and annoyed with myself. Especially after the match. The gaffer never really had a go at me. I knew from his body language – 'how much more, Roy?'," he added.
"I saw him the next day and I said 'I've had enough' – and I meant it. I came back that night and I waited, didn't sleep a wink. I spoke to Theresa [Keane's wife] when I got back and she said 'you're mad' and I said 'I know that but…'
"I never trained the Monday, or the Sunday, and he came round on the Monday in afternoon, and we had a good chat.
"He said 'you'll miss it' and I was convinced I wouldn't but I suppose deep, deep, very deep down of course I knew I would miss walking out at Old Trafford. I loved playing at Old Trafford and I loved playing for United. Full stop."
Keane went on cement his legacy at Manchester United by becoming one of the most decorated captains in Premier League history, lifting seven league titles.