Sydney Roosters playmaker Luke Keary is backing his teammate and close friend Lindsay Collins to bounce back from a second serious concussion in as many weeks.
An ACL injury last season kept Collins to only 22 games in the past 18 months, during which time he suffered three serious concussions.
Collins left the field concussed in the third State of Origin game on July 13 and in his first game back for the Roosters on Thursday night, he lasted less than half an hour before going down again.
The Roosters have yet to put a time frame on Collins' return but he looks likely to need more than the seven days mandated by HIA protocols.
No Rooster is feeling for Collins more than Keary.
The pair became especially close last season when they were forced to stay behind in Sydney to rehab their ACL injuries while the NRL relocated to Brisbane.
On top of that, Keary has an extensive concussion history of his own - the five-eighth suffered five head knocks across 2018 and 2019 and when he concussed himself against Melbourne in round 14 the club gave him six weeks off to recover.
"I'm really close to 'Linds' so I know what he's been through," Keary told AAP.
"We were in Sydney together last year so we spent every day together, rehabbing our legs in lockdown.
"It's hard to watch (the concussion)."
But Keary is reassuring his mate that he's living proof you can bounce back from concussions with the right support.
"I know he'll be okay. He'll go see the people he needs to see and get the right advice," Keary said.
"He was in good spirits (after the game)."
Keary shook off most of his concussion symptoms a month ago but only made his return from concussion last weekend, when the Roosters thrashed Newcastle.
The Roosters were below their best in the follow-up against Manly but Keary said he was just grateful to have made it through another game post-concussion.
"I was just really happy to be back last week and then just kind of happy to get through that one (against the Sea Eagles)," he said.
"It was just all over the shop but super happy to be back."
Keary's chemistry with halves partner Sam Walker has been subject to scrutiny this season but things appear to have improved since the 30-year-old returned from his concussion.
Having begun the season directing traffic at halfback, Keary is back playing five-eighth where he starred for the Roosters in their 2018 and 2019 premiership seasons.
"I like being on the left side," he said.
"I've played my whole career there. I'm comfortable with it and I'm familar with it."