YORK City Knights' loan signing Junior Vaivai has bravely opened up about his struggles with mental health.

Speaking to parent club Hull KR's website in the form of a letter to himself, the American international discussed the toll of recurring injuries, his break from professional rugby league and his young son - as well as a six-month period where he "did not leave the house".

He did so to help boost recognition of Mental Health Awareness Week.

The 29-year-old has made an immediate impression at the Knights, scoring one and creating the winner in the 16-12 win at Widnes Vikings last week.

Auckland-born Vaivai qualifies to play for the USA through his American-Samoan grandmother, though he spent much of his childhood in New Zealand and Australia.

As a junior, he featured for Queensland-based sides Goodna Eagles and Easts Tigers before making his NRL debut for South Sydney Rabbitohs in 2009.

Following a series of ACL injuries and challenging conditions on and off the field, by 2013 Vaivai's passion for the game had waned - until a chat with older cousin Dwayne 'The Rock' Johnson convinced him to retake to the field.

He went back to his roots, playing in humble parks for Wests Illawarra, and worked his way back up to internationally-recognised stadia.

Centre Vaivai was named in the States' 23-man squad for the 2017 World Cup and signed for KR in February 2018.

"Dear me," he began. "I know it's been a while, but I am grateful to my Father in Heaven for the life of experiences He has blessed me with over the last 10 years.

"These experiences have helped me become the person I am today.

"To be honest, these experiences weren't all sunshine and rainbows.

"There was a time where I was hit with serious injuries, which caused me to hate the one thing I loved, which was playing the game of rugby league, with all of this frustration and hate towards the one thing I really loved because of the injuries that I endured.

"In 2013, I made the decision to leave after rupturing my ACL for the third time.

"At this point, I found myself in a very dark place. For six months straight, I did not leave the house. I sat at home with all the blinds closed, isolating myself from the world.

"All I could think about during that time was what I was going to do now.

"I have a two-year-old boy who is depending on me to be a father that will love, guide, protect and, most importantly, be a role model to him.

"With all of the negative thoughts that were going through my head about where life was at the time and where it could possible end up if I continued to have a negative outlook on life, I decided to get up, dust myself off and open the blinds.

"From that day forwards, I promised myself to do all I could to play rugby league at a professional level again.

"I knew it was going to take a lot of hard work and sacrifice.

"However, I saw this as an opportunity to show my son that things in life aren't given to you - they are earned. Making sure he understands and can see that the world meets no one halfway.

"So if you want something, you go and get it and don't let anyone tell you you can't.

"Little did I know, six years later, all the hard work and sacrifice paid off.

"In May 2018, I made my return to professional rugby league when I was signed by Hull Kingston Rovers."

He added: "Be mindful of the people you come into contact with, get to know them before you judge them.

"It is never weak to speak and, remember, it is not about what you say, it is the way you say things that determines what message resonates with that person.

"Someone once said, 'Unfortunately, we don't get to choose the cards we are dealt in life'. Just remember, it's not the cards you are dealt, it's the way you play the cards that will determine the outcome of your life."