When do players know it's time to retire?

"… You just know…"

You hear this all the time when you are talking to NRL players, who have decided to end their playing careers.

We heard Greg Inglis say it earlier this month.

But how do they know? Is it one thing, or many things? Is it mind over body, or a body starting to break down?

In Brent Tate's case it was just that.

"When I did my knee in 2010 I always knew I was one more reconstruction away from finishing," said Tate, who underwent four of those operations.

"I was contracted to finish up in 2015 but when I did my knee again in 2014, I thought 'Nup. Enough is enough'."

Shane Webcke's departure from the Broncos was over a knee, similar to Tate's from the Cowboys.

But Webcke doesn't put himself in the "…you just know" category.

"It was my knee telling me 'I don't want to play any more'," Webcke said.

"I thought I had to go because I knew enough about myself that you play how you train. You start cutting corners at training it's not long before you start doing it in a game.

"So in that sense I did know. But my form hadn't deserted me – certainly the knee got me too early. I noticed Greg [Inglis] was the same age as me [32] when he retired.

"I know it's a combination of things with him but his form hadn't deserted him either. He might have lost a little but he was still masterful.

"I think there's a time – for whatever reason – that it does become obvious and that is seen by other people and that helps you.

"So instead of people around you saying 'What are you doing going too early?' they are all saying 'Yep. That's the right decision'.

"In the cut and thrust of the NRL today, where the salary cap is so pertinent, I don't know if you can go one or two years longer than you want to anyway."

Michael Ennis just knew.

"I'd love the game so much and put so much into it, I just felt I couldn't keep putting in that much preparation to play at the level that would make me content," Ennis said.

"The things I used to really love doing, I started to find hard. One thing that comes to mind is the monotony of weight training, when I didn't mind it at all the start of my career.

"Game day is supposed to be the best day of the week. But I started to look down the other end of the field during the warm-up and thinking 'Really? I've got a fair challenge in front of me but am I up for it?'

"I was really methodical with my routine, ticking all the boxes like 'What time have I got to eat? What time do I need to sleep? What time do I need to stretch?' But that puts a lot of pressure on a lot of areas of your life. So when it does, you know it's time.

"Physically, at the back end of my career, I'd never felt better so it wasn't the body."

Webcke and Ennis have been to one or two games where they felt a pull to play again. For Tate it happened only once.

"The 2015 grand final. But other that, no other time. I don't miss the game – I loved it, don't get me wrong. But I gave it my all so I don't miss it."

All three – Webcke (254 games), Tate (229) and Ennis (274) – finished before the much-vaunted '300 Club'. Do players look at their NRL game tally to see if it's enough, or close to a milestone, before they retire?

"Everyone cares about that to an extent because it's a measure of how far you went in the game. But the reality is once upon a time 150 was a lot of games," Webcke said.

"That figure then grew to 200, then 250 became a lot of games and now 300 is the new 200.

"I know some players might think about statistics and think 'How do I stack up?' but people do not remember statistics. This is very important in my opinion.

"They don't remember how many games you played, they remember how you played them.

"Gorden Tallis played 214 games. But when he played on any given day it was something to behold. That's what people remember."

Webcke and Ennis both finished by lifting the Telstra Premiership trophy for their clubs. Tate should have.

"Someone told me early in my career that 'Fairytales are for children's books' so I always believed that," he said.

"I was OK with the way I finished. I always had the mindset that I was thankful for what I got and didn't worry for what I didn't have.

"I always made sure that I didn't look back and be dirty on what I missed out on. I played for 14 years – how good – and that really helped me with retirement."