The family of Jarrod Mullen has reached out to NRL boss Todd Greenberg, urging him to consider reducing the former Newcastle star's four-year doping ban.
Mullen, 30, was suspended under the NRL's anti-doping policy this year after he tested positive to steroid Drostanolone.
His mother Leeann said the ex-playmaker had put on a brave face but was in "deep despair" over the suspension.
She wrote to Greenberg in the hope of a downgrade, admitting her son made a mistake but lamenting a purported failure to take his good on and off-field behaviour into account.
"Obviously, four years is, in my view, very, very harsh," Leeann Mullen told ABC radio on Tuesday.
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"There's been a whole range of off-field issues that NRL players have been embroiled in. I believe most of them have got off fairly lightly compared to a four-year ban imposed on Jarrod."
She said the pressure on Mullen as an NRL player affected his decision making around seeking of treatment for an hamstring problem late last year - one of a series of injuries that had plagued his career.
She said Mullen did not advertently or consensually take the banned substance, supporting her son's previous comments that he received treatment from a trusted physiotherapist outside of the Newcastle club before testing positive.
"He's been under constant pressure his whole NRL career. He came in as an 18 year old, expected to be or to replicate Andrew Johns," Leeann Mullen said.
"With the hamstring injuries, he knew that his time was limited ... He was hearing the whispers that the Knights wanted to get rid of him.
"And he went to a physiotherapist that had treated him for 10 years. So it was nothing new. He just went to have his dry needling, which he had done for 10 years.
"Yes, he was trying to fix an injury and he believes he was having an amino acid to fix that.
"He can probably think back now that he was not in the right mindset to ask more questions."
Leeann Mullen also has criticised the Knights' handling of his ban, claiming a lack of support but not specifying what more the club could have done.
"He's certainly been hung out to dry, I believe," she said.
"I feel that that support hasn't been forthcoming.
"I don't know how much they can do or what they can do, but ... there's a player that's in deep despair."
Newcastle said they understood it was an emotional time for the Mullen family but support was available.
"The club has offered support to Jarrod and his family throughout this difficult time and remain as disappointed as his family in regard to the premature end of his career at the club," Newcastle said in a statement to AAP.
