It's one of the great travesties that only the select few, and not always the good guys, get the fairytale finish.

In Glasby's case, he would have been too dazed to initially even see the finish coming. A series of concussions, the last during a clash with the Cowboys in Townsville back in late June, was the beginning of the end for the veteran forward.

After experiencing on-going concussion symptoms following that game, he hasn't played since and after extensive neurological testing, has been given the green light by the NRL to medically retire.

It means instead of playing an active role in the club's first finals appearance in seven years, he will be watching from the stands like the rest of us.

To be fair, the 31-year-old former Queensland Origin forward has been preparing for Sunday's farewell for quite some time. But he said it has still been an emotional week.

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"It has been pretty emotional telling the players and obviously being out there tonight [on the field]," he said after the big win over the Dragons.

"Saying farewell officially is I suppose a bit emotional but at the same time, I've known it's been coming for a bit so I've had time to wrap my head around it."

Glasby said he knew his time as a player in the game was up when "scary" symptoms from his last concussion persisted for weeks and kept re-occurring.

"When I was still getting symptoms a fair while after the last concussion, I knew that was going to be it," he said.

"I was in a bad way for a bit. I've had knocks in the past where I've had symptoms for a week or so but nothing like this. That part of it was scary because I knew there was some part of it that was getting a bit worse."

Asked about the symptoms, he said: "Headaches, sensitivity to light, noise, I was getting motion sickness on the bus with the boys to the game.

"It would go away and I'd feel good for a day and I'd just over-stretch a little bit mentally or physically and it would all come back and it would come back bad. It was no good.

"It was scary but I had the re-assurance I would recover from the particular symptoms that I had and I have so that's been good. I haven't had anything for a little bit now so that's been good.

"It was very frustrating and I just felt a bit useless and I couldn't do anything. It wasn't real nice and like I said, I just knew I didn't want to keep risking doing that. I followed the medical advice. It wasn't just me deciding."

As for the potential long-term effects of all the head knocks he has had during his career, he said:

"There is some concern there definitely but they don't know enough about it to give a definite answer on it."

After a career spanning eight seasons and 138 NRL games for Melbourne, where he won a premiership, and Newcastle, Knights coach Adam O'Brien said Glasby's health came first.

"I've known Tim for a long time and [wife] Casey and the kids and his number one job on this earth is to be a good father and good husband and a footy player third.

"So it was an easy decision in the end once I'd talked to Tim and understood what was going on."

O'Brien said Glasby can be proud of a career shaped by hard work and a desire to succeed after over-coming rejection when he was unwanted, coming out of the Under 20's at the Penrith Panthers, forcing him to return home to Rockhampton.

"I know the narrative around this is going to be all about the concussion stuff but there's a player there that got absolutely every ounce out of his career," he said.

"He typifies exactly what hard work and determination can get you in life. All of his success at club and representative level has come on the back of hard work.

"I have been very fortunate to spend over a decade with Tim and share some special moments in the NRL with him. He's also been a huge help with my transition into head coaching."