King saw a surgeon on Wednesday and will go under the knife in coming weeks after tearing an anterior cruciate ligament in the opening week of NRL trials on Saturday night in Papua New Guinea.

The popular No.9 took to social media on Tuesday night to say he had a "broken heart" and "would be lying if he said he was okay".

King will remain around the club as part of the rehabilitation group, while his welfare will also be of a high priority.

His mother, Amanda King, is on the club's welfare team which is led by former Gold Coast and Parramatta winger Jordan Aitken.

The pair will keep close contact with the 28-year-old, with Aitken having been part of the crew who carried him from the field.

"He's doing well, he's obviously disappointed ... He has been through similar experiences and has a really supportive partner and family," Aitken told AAP.

"Josh Dugan and I were there with him after because we had a fair indication of the injury.

"I am obviously in touch with him regularly. (Coach) John Morris is great, I am with the players every day having lunch with them.

"And then I'll use some of the senior players, like Jayson Bukuya might take him out for a coffee or Andrew Fifita might encourage him into community work."

The NRL's wellbeing space has improved dramatically, with clubs adept at dealing with injuries and managing players through recovery when they often feel on the outer.

"There are a number of ways you manage it," Aitken said.

"From an off-field perspective it's about engagement, whether that is education, employment or mentoring of young players.

"With the support of the NRL there is access available for players to psychologists."

King's injury couldn't have come at a tougher time.

Unsigned by Parramatta in 2018 after 43 NRL games, he played a year of second-tier English football before battling to return to Australia in 2020.

"Shattered. Broken heart it's still sinking in that my season is over," King tweeted on Tuesday night.

"I'm taking things 1 day at a time and determined to not let this defeat me physically or mentally. Thank you all for the support."

Australian Associated Press