Cronulla Sharks veteran Luke Lewis said learning to deal with the mental and physical lows that rugby league dishes up is just as important as enjoying the highs.

With 15 teams left disappointed each year it's the support of family, the camaraderie with teammates and a passion for the game that helps ease the pain of tough times.

Lewis, the Sharks' State of Mind Ambassador, who himself has had his share of ups and downs during 17 years of first-grade, told NRL.com he's there to give a helping hand to anyone that may be going through a rough patch.

"There's so many different aspects of the game where you ride emotional roller coasters," Lewis said.

"You have years where everything goes really good for you and you don't have a drama in the world and then some years you have injuries and you find it hard to find your feet back on the park and you go through the form slumps just to get back to where you were before, then the game grows so you have to adjust to that.

Match Highlights: Sharks v Sea Eagles - Round 21, 2018

"I've been fortunate enough to be in the game for a long time and experience all those different emotions and opportunities and now I'm glad that I'm able to give back being an ambassador - if I could help just one person I'd be happy with that."

Lewis' career is the stuff of legend - two premierships (2003 and 2016), a Clive Churchill Medal, 17 appearances for NSW and 16 Test matches.

The NRL supports the mental health of its players through the game's State of Mind program.

There are many things on and off the field that can shift your mindset and for Lewis it's about putting things into perspective and knowing he has a strong support system behind him.

"We are so competitive and you always want to be at the top of your game but the reality is you can't be at the top the whole time - you're going to have weeks where you're off, you're going to have weeks when things aren't working for you but then you have weeks and months where everything's just flowing," Lewis said.

"There's been heaps of times where I just don't talk to anyone, I want to get out of training as quick as I can, I just want to go and chill out down at the beach by myself and I don't really know why.

"But then you look at little things like your family that put everything into perspective and you get back on the training park with your mates, you have one good week and the next thing you know you've forgotten about it the tough times."

With Lewis retiring at the end of 2018, the 34-year-old faces yet another challenge of making the transition from player to retiree.

In a perfect world the second-rower said he'd happily play rugby league forever, but unfortunately, he's forced to make the tough switch as the body take its course.

He is uncertain regarding his post-football plans but after playing 317 NRL games, coaching may be on the cards.

"I have no idea what's happening after footy just yet, I've got my hands in a few little things but nothing in concrete just yet," Lewis said.

"I'll try and nut something out the next couple of months, but I definitely want to do some travelling in the meantime.

"It's [coaching] something I'd really love to do. I've learnt so much through the game and I think I can definitely give back to the game."